Skin absorption through atopic dermatitis skin: a systematic review

Potential impact of underlying diseases influencing ADME in nonclinical safety assessment

Nonclinical studies involve in vitro, in silico, and in vivo experiments to assess the toxicokinetics, toxicology, and safety pharmacology of drugs according to regulatory requirements by a national or international authority. In this review, we summarize the potential effects of various underlying diseases governing the absorption, distribution, metabolism, and excretion (ADME) of drugs to consider the use of animal models of diseases in nonclinical trials. Obesity models showed alterations in hepatic metabolizing enzymes, transporters, and renal pathophysiology, which increase the risk of drug-induced toxicity. Diabetes models displayed changes in hepatic metabolizing enzymes, transporters, and glomerular filtration rates (GFR), leading to variability in drug responses and susceptibility to toxicity. Animal models of advanced age exhibited impairment of drug metabolism and kidney function, thereby reducing the drug-metabolizing capacity and clearance. Along with changes in hepatic metabolic enzymes, animal models of metabolic syndrome-related hypertension showed renal dysfunction, resulting in a reduced GFR and urinary excretion of drugs. Taken together, underlying diseases can induce dysfunction of organs involved in the ADME of drugs, ultimately affecting toxicity. Therefore, the use of animal models of representative underlying diseases in nonclinical toxicity studies can be considered to improve the predictability of drug side effects before clinical trials.

Supercritical CO2 fluid extract from Stellariae Radix ameliorates 2,4-dinitrochlorobenzene-induced atopic dermatitis by inhibit M1 macrophages polarization via AMPK activation

Yin chai hu (Radix Stellariae) is a root medicine that is frequently used in Chinese traditional medicine to treat fever and malnutrition. In modern medicine, it has been discovered to have anti-inflammatory, anti-allergic, and anticancer properties. In a previous study, we were able to extract lipids from Stellariae Radix using supercritical CO2 extraction (SRE), and these sterol lipids accounted for up to 88.29% of the extract. However, the impact of SRE on the development of atopic dermatitis (AD) has not yet been investigated. This study investigates the inhibitory effects of SRE on AD development using a 2,4-dinitrochlorobenzene (DNCB)-induced AD mouse model. Treatment with SRE significantly reduced the dermatitis score and histopathological changes compared with the DNCB group. The study found that treatment with SRE resulted in a decrease of pro-inflammatory cytokines TNF-α, CXC-10, IL-12, and IL-1β in skin lesions. Additionally, immunohistochemical analysis revealed that SRE effectively suppressed M1 macrophage infiltration into the AD lesion. Furthermore, the anti-inflammatory effect of SRE was evaluated in LPS + INF-γ induced bone marrow-derived macrophages (BMDMs) M1 polarization, SRE inhibited the production of TNF-α, CXC-10, IL-12, and IL-1β and decreased the expression of NLRP3. Additionally, SRE was found to increase p-AMPKT172, but had no effect on total AMPK expression, after administration of the AMPK inhibitor Compound C, the inhibitory effect of SRE on M1 macrophages was partially reversed. The results indicate that SRE has an inhibitory effect on AD, making it a potential therapeutic agent for this atopic disorder.

Topical steroids or emollients: does order matter?

Topical corticosteroids, topical steroid-sparing agents, and emollients are all used to treat atopic dermatitis. However, there are no formal guidelines dictating the order and timing in which these topical modalities should be applied. Additionally, the order of application may change drug absorption, efficacy, and distribution. This is especially important for patients with atopic dermatitis. These patients have a dysfunctional skin barrier, which can lead to greater systemic absorption of drugs. Moreover, children already have an increased rate of systemic absorption due to a higher ratio of body surface area to body weight. Thus, the order of application of topical regimens is of the utmost importance in pediatric dermatology. This manuscript presents an updated review of the literature with a focus on guiding clinicians toward the best practices from the available resources.

Preclinical pharmacokinetic investigation of the bioavailability and skin distribution of HY-072808 ointment, a novel drug candidate for the treatment of atopic dermatitis, in minipigs by a newly LC-MS/MS method

HY-072808 is a novel phosphodiesterase 4 inhibitor clinically used for topical atopic dermatitis treatment. Cytochrome P450 enzymes are involved in transforming it into major metabolite ZZ-24. An efficient UPLC-MS/MS method was established to detect HY-072808 and ZZ-24 in plasma and skin tissues of minipigs.One-step protein precipitation was performed with acetonitrile. Subsequently, elution was served with a methanol and water gradient containing 0.1% formic acid for 3.5 min. The plasma and skin tissue concentrations of HY-072808 and ZZ-24 showed good linearity from 0.200 to 200 ng/mL.The experimental minipigs exhibited low systemic exposure and bioavailability of 3.1-7.6% after transdermal application of 1-4% HY-072808 ointment. Multiple topical administrations over seven consecutive days showed a minor accumulation in systemic exposure, with accumulation factors of 2.3 and 4.0 for HY-072808 and ZZ-24, respectively.The distribution of HY-072808 ointment among different cortical layers in minipigs was studied for the first time. Following transdermal application of 2% HY-072808 ointment, the concentration in plasma and skin tissues in the order of epidermis > dermis > subcutaneous tissue ≈ subcutaneous muscle ≈ plasma; at 48 h after the administration, the epidermis and dermis still had a high concentration of the drug.

A Review of Anti-Inflammatory Phytoconstituents Used in Herbal Cosmeceuticals for the Treatment of Atopic Dermatitis

Skin diseases such as atopic dermatitis affect babies, children, and adults and are characterized by red skin/spots, severe itching that appears on the face, head, legs, neck, and hands, and various causes of illness caused by various external and internal factors. AD is a type IIgE-mediated hypersensitivity reaction. Herbal preparations treat various dermatological diseases like dry skin, melasma, acne, and eczema. Cosmeceuticals are the connection between cosmetics and medicine, one of the world's most used forms of medicine. Cosmeceuticals products are beneficial in treating AD. Herbal cosmetics play a major role in curing various skin diseases. Today, various herbs used in cosmeceuticals have anti-inflammatory, antioxidant, antibacterial, and antiseptic effects. Compared to synthetic preparations, herbal preparations have fewer side effects. This review paper introduces Atopic dermatitis, cosmeceutical, and various phytoconstituents like gallic acid, ferulic acid, boswellic acid, quercetin, and naringenin tetra hydroxyl flavanol glycoside, glycyrrhizic acid, epigallocatechin gallate, etc., used in atopic dermatitis.

Adherence in Atopic Dermatitis

Atopic dermatitis is a chronic dermatologic condition requiring extended treatment times with topical application of medications. While atopic dermatitis treatments can be highly effective when used as directed, oftentimes patients do not respond as expected, raising concern for nonadherence versus nonresponse. This chapter aims to describe what is currently known about adherence in atopic dermatitis and to discuss strategies to improve adherence in order to improve treatment outcomes. Whether intentional or unintentional, nonadherence to treatment can limit patient outcomes of this disease for a variety of reasons. These include frustration with medication efficacy, inconvenience, and fear of side effects. Other factors include forgetfulness, financial burden of treatment, lack of trust in the physician, dislike of prescribed medication, or lack of understanding of disease or treatment. Several interventions have been studied with the aim of improving adherence in atopic dermatitis-such as educational workshops for patients and caregivers, earlier follow-up visits, and text messages reminders-however, these are often limited by sample size and power. Further research is needed to study both specific patterns of nonadherence in atopic dermatitis, as well as methods to improve them.

Increased Risk of Renal Malignancy in Patients with Moderate to Severe Atopic Dermatitis

BACKGROUND

Evidence for an association between atopic dermatitis (AD) and cancer is still insufficient. In particular, the association between the risk of renal malignancy and the severity of AD has not been thoroughly investigated.

OBJECTIVE

To investigate the risk of renal malignancy and determine the association between AD severity and cancer risk using data from the Korean National Health Insurance Service (KNHIS) database.

METHODS

We performed a population-based cohort study using the National Health Claims database from the NHIS in Korea.

RESULTS

We found a statistically significant association between AD and overall malignancy (for mild AD, hazard ratio (HR): 1.061, 95% confidence interval (CI): 1.006-1.118; for moderate to severe AD, HR: 1.061, 95% CI: 1.014-1.11) compared with the no AD group. The moderate to severe AD group showed a significantly increased risk for renal malignancy (adjusted HR: 1.533, 95% CI: 1.209-1.944) compared with the no AD group.

LIMITATIONS

Patient inclusion is solely based on diagnostic codes. We had no data about drug use, genetic factors, or other medical history that could affect the cancer risk.

CONCLUSION

In our large population-based cohort study, moderate to severe AD was associated with increased risk of renal malignancy. Regular check-ups for renal malignancy are recommended in this population.

Comparison of lotions, creams, gels and ointments for the treatment of childhood eczema: the BEE RCT

Background

Emollients are recommended for children with eczema (atopic eczema/dermatitis). A lack of head-to-head comparisons of the effectiveness and acceptability of the different types of emollients has resulted in a 'trial and error' approach to prescribing.

Objective

To compare the effectiveness and acceptability of four commonly used types of emollients for the treatment of childhood eczema.

Design

Four group, parallel, individually randomised, superiority randomised clinical trials with a nested qualitative study, completed in 2021. A purposeful sample of parents/children was interviewed at ≈ 4 and ≈ 16 weeks.

Setting

Primary care (78 general practitioner surgeries) in England.

Participants

Children aged between 6 months and 12 years with eczema, of at least mild severity, and with no known sensitivity to the study emollients or their constituents.

Interventions

Study emollients sharing the same characteristics in the four types of lotion, cream, gel or ointment, alongside usual care, and allocated using a web-based randomisation system. Participants were unmasked and the researcher assessing the Eczema Area Severity Index scores was masked.

Main outcome measures

The primary outcome was Patient-Oriented Eczema Measure scores over 16 weeks. The secondary outcomes were Patient-Oriented Eczema Measure scores over 52 weeks, Eczema Area Severity Index score at 16 weeks, quality of life (Atopic Dermatitis Quality of Life, Child Health Utility-9 Dimensions and EuroQol-5 Dimensions, five-level version, scores), Dermatitis Family Impact and satisfaction levels at 16 weeks.

Results

A total of 550 children were randomised to receive lotion (analysed for primary outcome 131/allocated 137), cream (137/140), gel (130/135) or ointment (126/138). At baseline, 86.0% of participants were white and 46.4% were female. The median (interquartile range) age was 4 (2-8) years and the median Patient-Oriented Eczema Measure score was 9.3 (SD 5.5). There was no evidence of a difference in mean Patient-Oriented Eczema Measure scores over the first 16 weeks between emollient types (global p = 0.765): adjusted Patient-Oriented Eczema Measure pairwise differences - cream-lotion 0.42 (95% confidence interval -0.48 to 1.32), gel-lotion 0.17 (95% confidence interval -0.75 to 1.09), ointment-lotion -0.01 (95% confidence interval -0.93 to 0.91), gel-cream -0.25 (95% confidence interval -1.15 to 0.65), ointment-cream -0.43 (95% confidence interval -1.34 to 0.48) and ointment-gel -0.18 (95% confidence interval -1.11 to 0.75). There was no effect modification by parent expectation, age, disease severity or the application of UK diagnostic criteria, and no differences between groups in any of the secondary outcomes. Median weekly use of allocated emollient, non-allocated emollient and topical corticosteroids was similar across groups. Overall satisfaction was highest for lotions and gels. There was no difference in the number of adverse reactions and there were no significant adverse events. In the nested qualitative study (n = 44 parents, n = 25 children), opinions about the acceptability of creams and ointments varied most, yet problems with all types were reported. Effectiveness may be favoured over acceptability. Parents preferred pumps and bottles over tubs and reported improved knowledge about, and use of, emollients as a result of taking part in the trial.

Limitations

Parents and clinicians were unmasked to allocation. The findings may not apply to non-study emollients of the same type or to children from more ethnically diverse backgrounds.

Conclusions

The four emollient types were equally effective. Satisfaction with the same emollient types varies, with different parents/children favouring different ones. Users need to be able to choose from a range of emollient types to find one that suits them.

Future work

Future work could focus on how best to support shared decision-making of different emollient types and evaluations of other paraffin-based, non-paraffin and 'novel' emollients.

Trial registration

This trial is registered as ISRCTN84540529 and EudraCT 2017-000688-34.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (HTA 15/130/07) and will be published in full in Health Technology Assessment; Vol. 27, No. 19. See the NIHR Journals Library website for further project information.

S. aureus virulence factors decrease epithelial barrier function and increase susceptibility to viral infection

Individuals with atopic dermatitis (AD) are highly colonized by Staphylococcus aureus and are more susceptible to severe viral complications. We hypothesized that S. aureus secreted virulence factors may alter keratinocyte biology to enhance viral susceptibility through disruption of the skin barrier, impaired keratinocyte differentiation, and/or inflammation. To address this hypothesis, human keratinocytes were exposed to conditioned media from multiple S. aureus strains that vary in virulence factor production (USA300, HG003, and RN4220) or select purified virulence factors. We have identified the S. aureus enterotoxin-like superantigen SElQ, as a virulence factor of interest, since it is highly produced by USA300 and was detected on the skin of 53% of AD subjects (n = 72) in a study conducted by our group. Treatment with USA300 conditioned media or purified SElQ resulted in a significant increase in keratinocyte susceptibility to infection with vaccinia virus, and also significantly decreased barrier function. Importantly, we have previously demonstrated that keratinocyte differentiation influences susceptibility to viral infection, and our qPCR observations indicated that USA300 S. aureus and SElQ alter differentiation in keratinocytes. CRISPR/Cas9 was used to knock out CD40, a potential enterotoxin receptor on epithelial cells. We found that CD40 expression on keratinocytes was not completely necessary for SElQ-mediated responses, as measured by proinflammatory cytokine expression and barrier function. Together, these findings support that select S. aureus virulence factors, particularly SElQ, enhance the susceptibility of epidermal cells to viral infection, which may contribute to the increased cutaneous infections observed in individuals with AD. IMPORTANCE Staphylococcus aureus skin colonization and infection are frequently observed in individuals with atopic dermatitis. Many S. aureus strains belong to the clonal group USA300, and these strains produce superantigens including the staphylococcal enterotoxin-like Q (SElQ). Our studies highlight that SElQ may play a key role by altering keratinocyte differentiation and reducing barrier function; collectively, this may explain the AD-specific enhanced infection risk to cutaneous viruses. It is unclear what receptor mediates SElQ's effects on keratinocytes. We have shown that one putative surface receptor, CD40, was not critical for its effects on proinflammatory cytokine production or barrier function.

Lipid-based nanoformulation optimization for achieving cutaneous targeting: niosomes as the potential candidates to fulfill this aim

The present study screened the utility of topically-applied nanoformulations to target the drugs/actives into the skin reservoir with the reduction of possible systemic absorption. The lipid-based nanoformulations selected in this study included solid lipid nanoparticles (SLNs), nanostructured lipid carriers (NLCs), nanoemulsions (NEs), liposomes, and niosomes. We loaded flavanone and retinoic acid (RA) as the penetrants. The prepared nanoformulations were assessed for their average diameter, polydispersity index (PDI), and zeta potential. An in vitro permeation test (IVPT) was utilized to determine the skin delivery into/across pig skin, atopic dermatitis (AD)-like mouse skin, and photoaged mouse skin. We found an increased skin absorption of lipid nanoparticles following the increase of solid lipid percentage in the formulations (SLNs > NLCs > NEs). The use of liposomes even reduced the dermal/transdermal selectivity (S value) to lessen the cutaneous targeting. The niosomes resulted in significantly greater RA deposition and reduced permeation in the Franz cell receptor compared to the other nanoformulations. The S value of the RA delivery via stripped skin was increased by 26-fold in the niosomes compared to the free RA. The dye-labeled niosomes displayed a strong fluorescence in the epidermis and upper dermis through the visualization of fluorescence and confocal microscopies. The cyanoacrylate skin biopsy manifested greater hair follicle uptake of the niosomes compared to the free penetrants by 1.5 to three-fold. The 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay indicated an increase in antioxidant ability from 55% to 75% after flavanone entrapment in the niosomes. In the activated keratinocytes, the niosomal flavanone could suppress the overexpressed CCL5 to the baseline control because of the facile cell internalization. After the formulation optimization, the niosomes with higher phospholipid amount had a superior effect in delivering penetrants into the skin reservoir, with limited permeation to the receptors.

Safety and Efficacy of Topical Calcineurin Inhibitors in the Treatment of Facial and Genital Psoriasis: A Systematic Review

Facial and genital psoriasis impairs quality of life and is challenging to treat because of increased percutaneous penetration and, consequently, increased risk of adverse effects. Topical calcineurin inhibitors are recognized as a valid off-label treatment for these sensitive skin areas, but data on safety and efficacy are limited. This systematic review of the literature included 24 of 3,322 studies (5 randomized controlled trials, 9 open-label studies, 2 case series and 8 case reports). All studies demonstrated positive efficacy; 11 studies found statistically significant reductions in psoriasis severity. Local stinging, burning and itching were the most common short-term adverse effects and were reported in 18 studies. Topical calcineurin inhibitors appear to have an important role in the treatment of facial and genital psoriasis. The drugs are effective and generally well-tolerated with few adverse effects.

Effects of topical corticosteroid versus tacrolimus on insulin sensitivity and bone homeostasis in adults with atopic dermatitis-A randomized controlled study

INTRODUCTION

Topical corticosteroids (TCS), used to treat atopic dermatitis (AD), have been associated with type 2 diabetes and osteoporosis in epidemiological studies, possibly explained by systemic absorption.

OBJECTIVES

We examined whether intensive daily whole-body TCS treatment over 2 weeks followed by twice weekly application for 4 weeks could elicit insulin resistance and increase bone resorption in adults with AD.

METHODS

A randomized parallel-group double-blind double-dummy non-corticosteroid-based active comparator study design was completed in Copenhagen, Denmark. Thirty-six non-obese, non-diabetic adults with moderate-to-severe AD were randomized to whole-body treatment with betamethasone 17-valerate 0.1% plus a vehicle once daily or tacrolimus 0.1% twice daily after washout. Insulin sensitivity assessed by the hyperinsulinemic-euglycemic clamp combined with tracer infusions and biomarkers of bone formation (P1NP) and resorption (CTX) were evaluated at baseline, after 2 weeks of daily treatment and after further 4 weeks of twice-weekly maintenance treatment.

RESULTS

AD severity improved with both treatments and systemic inflammation was reduced. After 2 weeks, we observed similar increase in peripheral insulin sensitivity with use of betamethasone (n = 18) and tacrolimus (n = 18). Bone resorption biomarker, CTX, was unchanged, while bone formation marker, P1NP, decreased after betamethasone treatment after both 2 and 6 weeks but remained unchanged in the tacrolimus arm.

CONCLUSIONS

Whole-body treatment with TCS leads to systemic exposure but appears not to compromise glucose metabolism during short-term use, which may be a result of reduced systemic inflammatory activity. The negative impact on bone formation could be regarded an adverse effect of TCS.

Comorbidities of atopic dermatitis-what does the evidence say?

Atopic dermatitis (AD) is a common disease that is associated with atopic and nonatopic comorbidities. There has been a growing interest in this area of AD, because presence or risk of comorbidities can in many ways impact the management of patients with AD. Thus, some treatments for AD may improve its comorbidities as well, whereas others may increase their risk. In this review article, we discuss various comorbidities of AD mostly on the basis of the results of recent multiple systematic reviews and meta-analyses to update readers about this rapidly developing area of dermatology. We emphasize the important information provided by studies presenting both relative risk and absolute risk, and show that AD is associated with, among others, atopic comorbidities such as asthma, rhinitis, and food allergy, nonatopic comorbidities such as ocular, psychiatric, infectious, endocrine, autoimmune, and cardiovascular diseases, and certain cancers. Clinicians need to be aware of these and be cognizant about positive and negative effects of existing and new treatments for AD.

Viola yedoensis Makino formula alleviates DNCB-induced atopic dermatitis by activating JAK2/STAT3 signaling pathway and promoting M2 macrophages polarization

BACKGROUND

Atopic dermatitis (AD), a common inflammatory skin disorder, severely affects the life quality of patients and renders heavy financial burden on patient's family. The Chinese medicine Viola yedoensis Makino formula (VYAC) has been widely used for treating various skin disorders. Previous studies have reported that VYAC is effective in relieving DNCB-induced AD and inflammation. However, the anti-inflammatory mechanism of VYAC is still ill-defined and poorly understood. This study aims to investigate the therapeutic effects of VYAC on DNCB-induced AD and to elucidate the underlying anti-inflammatory mechanisms.

METHODOLOGY

VYAC were extracted with 70% ethanol and lyophilized for use. AD mice were established by DNCB. The therapeutic effects of VYAC were evaluated by oral administration VYAC (150, 300 and 600 mg/kg) daily in vivo. The histopathological and immunohistochemistry were used to analyze skin lesion and macrophages infiltration, RT-qPCR and Elisa were used to analyze the inflammatory factors in skin tissues and serum. To explore the underlying mechanism of VYAC against AD in vitro. RAW264.7 cells and bone-marrow-derived macrophages (BMDMs) were employed for macrophage polarization analysis. Flow cytometer, immunofluorescence and western blot were used to analyze M2 macrophages markers. STAT3 siRNA were transfected into both cells to validate the effects of VYAC-induced macrophages M2 polarization via JAK2/STAT3 signaling pathway.

RESULTS

VYAC ameliorated skin lesion of DNCB-induced AD mice by decreased clinical scores and epidermal thickness, decreased the level of pro-inflammatory factors (IL-1β, TNF-α and IL-18) and enhanced IL-10 anti-inflammatory factor level, inhibited macrophages infiltration and promoted M2 macrophages polarization in vivo. VYAC significantly promoted M2 macrophages polarization in vitro. It is observed that VYAC not only inhibited the phosphorylation of JAK2 and STAT3 in RAW264.7 cells and BMDMs, but also accelerated the translocation to the nucleus. What's more, VYAC reduced the polarization of M2 macrophage by activating JAK2/STAT3 signaling pathway was observed in both cells.

CONCLUSIONS

Our findings demonstrate that VYAC significantly ameliorates skin lesion of DNCB-induced AD mice and reduces the levels of inflammatory factors by activating JAK2/STAT3 signaling pathway and promoting M2 macrophages polarization.

National Saudi Consensus Statement on the Management of Atopic Dermatitis (2021)

Atopic dermatitis (AD) is a chronic inflammatory skin disease with an increasing prevalence regionally and globally. It is characterized by intense itching and recurrent eczematous lesions. With the increase in the availability of treatment options for healthcare practitioner and patients, new challenges arise for treatment selection and approach. The current consensus statement has been developed to provide up-to-date evidence and evidence-based recommendations to guide dermatologists and healthcare professionals managing patients with AD in Saudi Arabia. By an initiative from the Ministry of Health (MOH), a multidisciplinary work group of 11 experts was convened to review and discuss aspects of AD management. Four consensus meetings were held on January 14, February 4, February 25, and March 18 of 2021. All consensus content was voted on by the work group, including diagnostic criteria, AD severity assessment, comorbidities, and therapeutic options for AD. Special consideration for the pediatric population, as well as women during pregnancy and lactation, was also discussed. The present consensus document will be updated as needed to incorporate new data or therapeutic agents.

Preservative Contact Hypersensitivity among Adult Atopic Dermatitis Patients

Atopic dermatitis (AD) is a chronic inflammatory disease characterised by an impaired skin barrier. The prolonged use of topical preparations containing medications, emollients, fragrances and preservatives may increase the risk of contact hypersensitivity (CHS). In the Allergy Outpatient Unit of the Department of Dermatology, Venereology and Dermatooncology of Semmelweis University, 5790 adult patients were patch tested between 2007–2021 with the European Environmental Baseline Series according to international standards. Among all the tested adult patients, 723 had preservative CHS (PCHS) and 639 had AD. Among the 723 PCHS patients, 68 (9.4%) had AD; the female to male ratio was 3:1 in this group. Out of 639 AD patients, 68 had PCHS (10.6%). In the AD-PCHS group, 83.8% had CHS to methylisothiazolinone (MI) (tested from 2014), 36.8% to Kathon CG^®, 16.2% to methyldibromo-glutaronitrile, 11.8% to paraben, 7.4% to formaldehyde, 4.4% to para-tert-butylphenol-formaldehyde resin and 1.5% to Quaternium-15. The most common concomitant PCHS combination was Kathon CG^® + MI. Most patients (32.4%) belonged to the age group of 21–30, and skin symptoms affected mostly the limbs and face. The most common other concomitant allergens were nickel, lanolin alcohol and balsam of Peru. Preservatives (especially MI and Kathon CG^®) are important contact allergens in adult AD, mostly among young women. The rate of AD in the PCHS group and the rate of PCHS in the AD group is remarkable; thus, the role of PCHS should be highlighted in the topical therapy and in the prevention of possible AD exacerbations.

Contact allergy in children with and without atopic dermatitis: an Italian multicenter study

Background

Contact allergy and atopic dermatitis (AD) are both common inflammatory T cell‐mediated diseases and many factors may influence the prevalence of contact allergy in AD patients. In children, their possible correlation was debated with conflicting results.

Objectives

The present study aimed to assess the prevalence of contact sensitivity in children and to investigate the association with AD.

Materials and methods

A retrospective multicentre study on children aged from 0 to 14 years patch tested between January 2017 and December 2018 was performed. Children were consecutively patch tested with the SIDAPA (Società Italiana Dermatologia Allergologica Professionale Ambientale) baseline series.

Results

Among the 432 children investigated for contact allergy, 125 (28.9%) showed a positive reaction to at least one of the allergens tested, with a higher prevalence of positive patch test reactions in girls (32.3%) than in boys (25.0%). The most frequent contact allergens were nickel sulphate (10.2%), cobalt chloride (6.7%), methylisothiazolinone (3.7%), fragrance mix‐2 (3.2%), potassium dichromate (2.8%), fragrance mix‐1 (2.1%) and methylchloroisothiazolinone/methylisothiazolinone (2.1%). One‐hundred‐three children (23.8%) suffered from AD showing a higher prevalence of positive patch test (36.9%) compared to children without AD (26.4%).

Conclusions

Despite the topic being still controversial, the present study suggests a consistent prevalence of contact allergy among children with higher sensitivity rate among children with AD than without AD.

Topical Bimiralisib Shows Meaningful Cutaneous Drug Levels in Healthy Volunteers and Mycosis Fungoides Patients but No Clinical Activity in a First-in-Human, Randomized Controlled Trial

Mycosis fungoides (MF) is a subtype of CTCL with a low incidence and high medical need for novel treatments. The objective of this randomized, placebo-controlled, double-blinded, first-in-human study was to evaluate safety, efficacy, cutaneous and systemic pharmacokinetics (PK) of topical bimiralisib in healthy volunteers (HVs) and MF patients. In this trial, a total of 6 HVs and 19 early-stage MF patients were treated with 2.0% bimiralisib gel and/or placebo. Drug efficacy was assessed by the Composite Assessment of Index Lesion Severity (CAILS) score, supported by objective measuring methods to quantify lesion severity. PK blood samples were collected frequently and cutaneous PK was investigated in skin punch biopsies on the last day of treatment. Local distribution of bimiralisib in HVs showed a mean exposure of 2.54 µg/g in the epidermis. A systemic concentration was observed after application of a target dose of 2 mg/cm² on 400 cm², with a mean C_avg of 0.96 ng/mL. Systemic exposure of bimiralisib was reached in all treated MF patients, and normalized plasma concentrations showed a 144% increased exposure compared to HVs, with an observed mean C_avg of 4.49 ng/mL and a mean cutaneous concentration of 5.3 µg/g. No difference in CAILS or objective lesion severity quantification upon 42 days of once-daily treatment was observed in the MF patient group. In general, the treatment was well tolerated in terms of local reactions as well as systemic adverse events. In conclusion, we showed that topical bimiralisib treatment leads to (i) meaningful cutaneous drug levels and (ii) well-tolerated systemic drug exposure in MF patients and (iii) a lack of clinical efficacy, in need of further exploration due to numerous unknown factors, before depreciation of topical bimiralisib as a novel therapeutic drug for CTCLs.

Evaluation of the effect of the interleukin-25 serum concentration on the intensity of the symptoms of atopic dermatitis and epidermal barrier

Introduction

Interleukin 25 (IL-25) is a cytokine with proinflammatory and anti-inflammatory effects, and its biological function of reciprocal epidermal hyperplasia and of inhibiting the filaggrin synthesis points to an essential role connecting the inflammatory process with damage to the epidermal barrier in the course of atopic dermatitis (AD).

Aim

To assess the IL-25 in serum concentration in AD patients and to analyse its possible correlation with the disease intensity and selected epidermal barrier parameters such as transepidermal water loss (TEWL).

Material and methods

The study involved 43 patients with AD and 22 healthy volunteers. The IL-25 concentration was measured using the ELISA method. The intensity of disease symptoms was investigated using W-AZS and EASI indicators. The epidermal barrier was evaluated using a Tewameter TM300 and Corneometer CM825.

Results

The concentration of IL-25 in serum was higher in the study group than in the control group. IL-25 serum concentration correlates with W-AZS/EASI in patients with a severe and moderate course of AD. The concentration of IL-25 affects the TEWL within the affected, evaluated skin surface.

Conclusions

An elevated IL-25 concentration in serum is characteristic for patients with moderate and severe AD intensity. The IL-25 concentration in serum correlates with TEWL and with the moisture level in the affected area. However, further studies are necessary to determine the role played by IL-25 in the course of the disease and how it affects the functional parameters of the epidermal barrier.

What are the highest yielding search strategy terms for systematic reviews in atopic dermatitis? A systematic review

The impact of search strategies on systematic reviews (SR) of atopic dermatitis (AD) is unknown. The purpose of this review was to evaluate search strategies used in SR of AD and their impact on the frequency of manuscripts identified. MEDLINE and EMBASE were searched for SR related to AD. Simulations were performed by running combinations of search terms in MEDLINE and EMBASE. Overall, 250 SR met inclusion criteria, of which 225 specified search strategies. SR using 5-6 terms (20.0% to 12.1%) or ≥ 7 (40.0% to 18.8%) terms decreased, whereas SR using 3-4 terms numerically increased (18.8% to 30.2%) and 1-2 terms remained similar (37.5% to 38.9%) from 1999-2009 to 2015-2019. The most commonly searched terms were "atopic dermatitis" (n = 166), followed by "eczema" (n = 156), "dermatitis atopic'" (n = 81), "atopic eczema" (n = 74), "neurodermatitis" (n = 59), "Besniers prurigo" (n = 29), "infantile eczema" (n = 27), and "childhood eczema" (n = 19). Simulations revealed that "eczema" and "atopic dermatitis" yielded the most hits. The number of search terms that maximized hits in MEDLINE and EMBASE was 5 and 4, respectively. Search strategies for AD were heterogeneous, with high proportions of search strategies providing few search hits. Future studies should use standardized and optimized search terms.

Topical drug delivery: History, percutaneous absorption, and product development

Topical products, widely used to manage skin conditions, have evolved from simple potions to sophisticated delivery systems. Their development has been facilitated by advances in percutaneous absorption and product design based on an increasingly mechanistic understanding of drug-product-skin interactions, associated experiments, and a quality-by-design framework. Topical drug delivery involves drug transport from a product on the skin to a local target site and then clearance by diffusion, metabolism, and the dermal circulation to the rest of the body and deeper tissues. Insights have been provided by Quantitative Structure Permeability Relationships (QSPR), molecular dynamics simulations, and dermal Physiologically Based PharmacoKinetics (PBPK). Currently, generic product equivalents of reference-listed products dominate the topical delivery market. There is an increasing regulatory interest in understanding topical product delivery behavior under 'in use' conditions and predicting in vivo response for population variations in skin barrier function and response using in silico and in vitro findings.

Association of Potent and Very Potent Topical Corticosteroids and the Risk of Osteoporosis and Major Osteoporotic Fractures

Importance

Systemic and inhaled corticosteroids negatively affect bone remodeling and cause osteoporosis and bone fracture when given continuously or in high doses. However, risk of osteoporosis and major osteoporotic fracture (MOF) after application of topical corticosteroids (TCSs) is largely unexplored.

Objective

To examine the association between cumulative exposure to potent and very potent TCSs and risk of osteoporosis and MOF.

Design, Setting, and Participants

This nationwide retrospective cohort study included 723 251 Danish adults treated with potent or very potent TCSs from January 1, 2003, to December 31, 2017. Data were obtained from Danish nationwide registries. Filled prescription data were converted in equipotent doses to mometasone furoate (1 mg/g). Data were analyzed from June 1 to August 31, 2019.

Exposures

Patients were considered exposed when they had filled prescriptions of cumulative amounts corresponding to the equivalent of at least 500 g of mometasone, using filled prescriptions of 200 to 499 g as the reference group.

Main Outcomes and Measures

The co-primary outcomes were a diagnosis of osteoporosis or MOF. Hazard ratios (HRs) adjusted for age, sex, socioeconomic status, medication use, and comorbidity were calculated with 95% CIs using Cox proportional hazards regression models.

Results

A total of 723 251 adults treated with the equivalent of at least 200 g of mometasone were included in the analysis (52.8% women; mean [SD] age, 52.8 [19.2] years). Dose-response associations were found between increased use of potent or very potent TCSs and the risk of osteoporosis and MOF. For example, HRs of MOF were 1.01 (95% CI, 0.99-1.03) for exposure to 500 to 999 g, 1.05 (95% CI, 1.02-1.08) for exposure to 1000 to 1999 g, 1.10 (95% CI, 1.07-1.13) for exposure to 2000 to 9999 g, and 1.27 (95% CI, 1.19-1.35) for exposure to at least 10 000 g. A 3% relative risk increase of osteoporosis and MOF was observed per doubling of the cumulative TCS dose (HR, 1.03 [95% CI, 1.02-1.04] for both). The overall population-attributable risk was 4.3% (95% CI, 2.7%-5.8%) for osteoporosis and 2.7% (95% CI, 1.7%-3.8%) for MOF. The lowest exposure needed for 1 additional patient to be harmed (454 person-years) was observed for MOF with exposure of at least 10 000 g.

Conclusions and Relevance

These findings demonstrate that use of high cumulative amounts of potent or very potent TCSs was associated with an increased risk of osteoporosis and MOF.

Assessing the compliance of systematic review articles published in leading dermatology journals with the PRISMA statement guidelines: A systematic review

Background

Reporting quality of systematic reviews and meta-analyses is of critical importance in dermatology because of their key role in informing health care decisions.

Objective

To assess the compliance of systematic reviews and meta-analyses in leading dermatology journals with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement guidelines.

Methods

This review was carried out in accordance with PRISMA guidelines. Included studies were reviews published across 6 years in the top 4 highest-impact-factor dermatology journals of 2017. Records and full texts were screened independently. Data analysis was conducted with univariate multivariable linear regression. The primary outcome was to assess the compliance of systematic reviews and meta-analyses in leading dermatology journals with the PRISMA statement.

Results

A total of 166 studies were included and mean PRISMA compliance across all articles was 73%. Compliance significantly improved over time (β = .016; P = <.001). The worst reported checklist item was item 5 (reporting on protocol existence), with a compliance of 15% of articles.

Conclusion

PRISMA compliance within leading dermatology journals could be improved; however, it is steadily improving.

Atopic skin diathesis rather than atopic dermatitis is associated with specific contact allergies

BACKGROUND

The association of atopic dermatitis (AD) and allergic contact dermatitis has been a matter of considerable uncertainty. Study results range from lack of any association to increased sensitization for multiple allergens, but fail to identify consistent allergen associations.

OBJECTIVE

We studied a large patch test cohort of patients stratified by their atopic skin diathesis using the Erlangen Atopy Score (EAS), independent of active skin disease.

METHODS

Retrospective multi-center data analysis from five departments of dermatology in Germany with 4,509 patients. Patients were grouped as "no atopic skin diathesis" (n = 2,165) and "atopic skin diathesis" (n = 1,743), according to EAS.

RESULTS

Significantly more individuals with atopic skin diathesis showed at least one positive patch test reaction to the baseline series compared to individuals without atopic skin diathesis (49.1 % vs. 38.3 %). In logistic regression analyses, atopic skin diathesis was associated with a significantly higher risk of sensitization to methylchloroisothiazolinone/methylisothiazolinone (OR 2.383) and methylisothiazolinone (OR 1.891), thiuram mix (OR 1.614), as well as nickel (OR 1.530), cobalt (OR 1.683), and chromium (OR 2.089).

CONCLUSIONS

Atopic skin diathesis proved to be the most important intrinsic risk factor for contact sensitization to few, specific allergens. Past or present AD was a less relevant variable.

Physiologically-Based Pharmacokinetic Modeling to Support Determination of Bioequivalence for Dermatological Drug Products: Scientific and Regulatory Considerations

Physiologically-based pharmacokinetic (PBPK) modeling and simulation provides mechanism-based predictions of the pharmacokinetics of an active ingredient following its administration in humans. Dermal PBPK models describe the skin permeation and disposition of the active ingredient following the application of a dermatological product on the skin of virtual healthy and diseased human subjects. These models take into account information on product quality attributes, physicochemical properties of the active ingredient and skin (patho)physiology, and their interplay with each other. Regulatory and product development decision makers can leverage these quantitative tools to identify factors impacting local and systemic exposure. In the realm of generic drug products, the number of US Food and Drug Administratioin (FDA) interactions that use dermal PBPK modeling to support alternative bioequivalence (BE) approaches is increasing. In this report, we share scientific considerations on the development, verification and validation (V&V), and application of PBPK models within the context of a virtual BE assessment for dermatological drug products. We discuss the challenges associated with model V&V for these drug products stemming from the fact that target-site active ingredient concentrations are typically not measurable. Additionally, there are no established relationships between local and systemic PK profiles, when the latter are quantifiable. To that end, we detail a multilevel model V&V approach involving validation for the model of the drug product of interest coupled with the overall assessment of the modeling platform in use while leveraging in vitro and in vivo data related to local and systemic bioavailability.

New Treatments for Atopic Dermatitis Targeting Skin Barrier Repair via the Regulation of FLG Expression

Atopic dermatitis (AD) is one of the most common chronic, inflammatory skin disorders with a complex etiology and a broad spectrum of clinical phenotypes. Despite its high prevalence and effect on the quality of life, safe and effective systemic therapies approved for long-term management of AD are limited. A better understanding of the pathogenesis of atopic dermatitis in recent years has contributed to the development of new therapeutic approaches that target specific pathophysiological pathways. Skin barrier dysfunction and immunological abnormalities are critical in the pathogenesis of AD. Recently, the importance of the downregulation of epidermal differentiation complex (EDC) molecules caused by external and internal stimuli has been extensively emphasized. The purpose of this review is to discuss the innovations in the therapy of atopic dermatitis, including biologics, small molecule therapies, and other drugs by highlighting regulatory mechanisms of skin barrier-related molecules, such as filaggrin (FLG) as a crucial pathway implicated in AD pathogenesis.

Topical therapy of atopic dermatitis with a focus on pimecrolimus

Atopic dermatitis (AD) is a chronic and relapsing, inflammatory skin disease characterized by impaired skin barrier function and immune system dysregulation that results in dryness, skin microbiome dysbiosis and intense pruritus. It is highly heterogeneous, and its management is demanding. Patients with AD are at greater risk of comorbidities such as attention-deficit hyperactivity disorder as well as other atopic diseases. Early-onset AD cases typically improve or resolve in late childhood; however, it is proposed that the prevalence of persistent or adult-onset AD is higher than previously thought. Basic therapy consists of emollient application and trigger avoidance, and when insufficient, topical corticosteroids (TCS) are the first-line treatment. However, corticophobia/steroid aversion and TCS side-effects, particularly on sensitive skin areas, lead to low compliance and insufficient disease control. Several long- and short-term randomized controlled and daily practice studies have demonstrated that topical calcineurin inhibitors, such as pimecrolimus, have similar anti-inflammatory effects to low-to-medium strength TCS, reduce pruritus and improve the quality of life of patients. In addition, pimecrolimus does not cause skin atrophy, is steroid-sparing and has a good safety profile, with no evidence for an increased risk of malignancies or skin infections. In general, pimecrolimus cream is well-accepted and well-tolerated, encouraging patient adherence and leading to its use by many physicians as a preferred therapy for children and sensitive skin areas.

Cutting Edge of the Pathogenesis of Atopic Dermatitis: Sphingomyelin Deacylase, the Enzyme Involved in Its Ceramide Deficiency, Plays a Pivotal Role

Atopic dermatitis (AD) is characterized clinically by severe dry skin and functionally by both a cutaneous barrier disruption and an impaired water-holding capacity in the stratum corneum (SC) even in the nonlesional skin. The combination of the disrupted barrier and water-holding functions in nonlesional skin is closely linked to the disease severity of AD, which suggests that the barrier abnormality as well as the water deficiency are elicited as a result of the induced dermatitis and subsequently trigger the recurrence of dermatitis. These functional abnormalities of the SC are mainly attributable to significantly decreased levels of total ceramides and the altered ceramide profile in the SC. Clinical studies using a synthetic pseudo-ceramide (pCer) that can function as a natural ceramide have indicated the superior clinical efficacy of pCer and, more importantly, have shown that the ceramide deficiency rather than changes in the ceramide profile in the SC of AD patients plays a central role in the pathogenesis of AD. Clinical studies of infants with AD have shown that the barrier disruption due to the ceramide deficiency is not inherent and is essentially dependent on postinflammatory events in those infants. Consistently, the recovery of trans-epidermal water loss after tape-stripping occurs at a significantly slower rate only at 1 day post-tape-stripping in AD skin compared with healthy control (HC) skin. This resembles the recovery pattern observed in Niemann-Pick disease, which is caused by an acid sphingomyelinase (aSMase) deficiency. Further, comparison of ceramide levels in the SC between before and after tape-stripping revealed that whereas ceramide levels in HC skin are significantly upregulated at 4 days post-tape-stripping, their ceramide levels remain substantially unchanged at 4 days post-tape-stripping. Taken together, the sum of these findings strongly suggests that an impaired homeostasis of a ceramide-generating process may be associated with these abnormalities. We have discovered a novel enzyme, sphingomyelin (SM) deacylase, which cleaves the N-acyl linkage of SM and glucosylceramide (GCer). The activity of SM deacylase is significantly increased in AD lesional epidermis as well as in the involved and uninvolved SC of AD skin, but not in the skin of patients with contact dermatitis or chronic eczema, compared with HC skin. SM deacylase competes with aSMase and β-glucocerebrosidase (BGCase) to hydrolyze their common substrates, SM and GCer, to yield their lysoforms sphingosylphosphorylcholine (SPC) and glucosylsphingosine (GSP), respectively, instead of ceramide. Consistently, those reaction products (SPC and GSP) accumulate to a greater extent in the involved and uninvolved SC of AD skin compared with chronic eczema or contact dermatitis skin as well as HC skin. Successive chromatographies were used to purify SM deacylase to homogeneity with a single band of ≈43 kDa and with an enrichment of >14,000-fold. Analysis of a protein spot with SM deacylase activity separated by 2D-SDS-PAGE using MALDI-TOF MS/MS allowed its amino acid sequence to be determined and to identify it as the β-subunit of acid ceramidase (aCDase), an enzyme consisting of α- and β-subunits linked by amino-bonds and a single S-S bond. Western blotting of samples treated with 2-mercaptoethanol revealed that whereas recombinant human aCDase was recognized by antibodies to the α-subunit at ≈56 and ≈13 kDa and the β-subunit at ≈43 kDa, the purified SM deacylase was detectable only by the antibody to the β-subunit at ≈43 kDa. Breaking the S-S bond of recombinant human aCDase with dithiothreitol elicited the activity of SM deacylase with an apparent size of ≈40 kDa upon gel chromatography in contrast to aCDase activity with an apparent size of ≈50 kDa in untreated recombinant human aCDase. These results provide new insights into the essential role of SM deacylase as the β-subunit aCDase that causes the ceramide deficiency in AD skin.

Allergic Contact Dermatitis and Concomitant Dermatologic Diseases: A Retrospective Study

BACKGROUND

Allergic contact dermatitis (ACD) can exist in the setting of other dermatologic conditions. It is known that the treatment of these conditions can cause ACD, increasing both diagnostic and treatment difficulty.

OBJECTIVE

The aim of this study was to determine the frequency of common dermatologic conditions in the setting of ACD and in specific patient populations.

METHODS

A retrospective database study was completed using Truven Health to collect information on patch-tested ACD patients. Demographics and diagnostic information were retrieved. Of those with ACD, the presence of 15 dermatologic diagnoses was investigated. Subanalyses were conducted for each condition, including International Classification of Diseases, 10th Revision code specificity, demographics, and diagnostic information.

RESULTS

A total of 6380 patients (76.83% female) were given a diagnosis of ACD via patch testing. Of those with concomitant disease, those most common include atopic dermatitis (23.98%), urticaria (16.69%), and acne (11.51%). Eight of the concomitant conditions were found to have statistical significance in comparing the average age of ACD diagnosis with the selected diagnoses (α = 0.05).

CONCLUSIONS

Common dermatologic diseases can exist concomitantly with ACD, many of which can be treated by compounds that precipitate or worsen preexisting ACD. The average age of the diagnosis varies from concomitant diagnoses, which can contribute to difficulty in ACD diagnosis and treatment.

Evaluating Dermal Pharmacokinetics and Pharmacodymanic Effect of Soft Topical PDE4 Inhibitors: Open Flow Microperfusion and Skin Biopsies

PURPOSE

To investigate the difference in clinical efficacy in AD patients between two topical PDE4 inhibitors using dermal open flow microperfusion and cAMP as a pharmacodynamic read-out in fresh human skin explants.

METHODS

Clinical formulations were applied to intact or barrier disrupted human skin explants and both skin biopsy samples and dermal interstitial fluid was sampled for measuring drug concentration. Furthermore, cAMP levels were determined in the skin biopsies as a measure of target engagement.

RESULTS

Elevated cAMP levels were observed with LEO 29102 while no evidence of target engagement was obtained with LEO 39652. In barrier impaired skin the dISF concentration of LEO 29102 was 2100 nM while only 33 nM for LEO 39652. For both compounds the concentrations measured in skin punch biopsies were 7-33-fold higher than the dISF concentrations.

CONCLUSIONS

Low unbound drug concentration in dISF in combination with minimal target engagement of LEO 39652 in barrier impaired human skin explants supports that lack of clinical efficacy of LEO 39652 in AD patients is likely due to insufficient drug availability at the target. We conclude that dOFM together with a pharmacodynamic target engagement biomarker are strong techniques for establishing skin PK/PD relations and that skin biopsies should be used with caution.

Long-lasting contact dermatitis in patients with atopic dermatitis or psoriasis

BACKGROUND

The aetiology of contact dermatitis, a common inflammatory skin disorder, is often complex and multifactorial.

OBJECTIVES

To describe the characteristics of patients with contact dermatitis who also have concomitant atopic dermatitis or psoriasis.

METHODS

Between 2000 and 2011, adult patients with chronic contact dermatitis (six months or more), which also had concomitant atopic dermatitis or psoriasis, were recruited for a descriptive retrospective study in a tertiary care Spanish hospital. Univariate and multivariate analyses were used for the analysis of the collected data.

RESULTS

76 patients with atopic dermatitis and 130 with psoriasis were recruited. The most frequent site of contact dermatitis in both groups was the hands. The most frequent clinically relevant allergen in both groups was nickel sulphate. According to multivariate logistic regression, a statistically significant association was found between facial contact dermatitis and atopic dermatitis (adjusted OR 0.2 95% CI: 0.05-0.8; P = 0.022). No differences were found between the groups for patch test results (adjusted OR 0.6 CI 95%: 0.3-1.3; P = 0.194).

CONCLUSIONS

Although the number of patients was limited, our results provide valuable insight on the behaviour of contact dermatitis in patients with atopic dermatitis and with psoriasis. Facial contact dermatitis was positively associated with atopic dermatitis. No differences were found with respect to rates of contact hypersensitivity or positivity to different allergens.

Normal insulin sensitivity, glucose tolerance, gut incretin and pancreatic hormone responses in adults with atopic dermatitis

AIM

To examine whether adults with mild to moderate atopic dermatitis (AD) had reduced insulin sensitivity and/or exhibited other gluco-metabolic disturbances compared with carefully matched healthy controls.

MATERIALS AND METHODS

Sixteen adult, non-obese, non-diabetic patients with mild to moderate AD and 16 gender-, age- and body mass index (BMI)-matched healthy controls underwent a hyperinsulinaemic euglycaemic clamp (insulin infusion rate: 40 mU/m² /minute) and an oral glucose tolerance test (OGTT) with frequent blood sampling for gut and pancreatic hormones.

RESULTS

The two groups were similar in age (33 ± 3 vs. 33 ± 3 years, mean ± standard error of the mean [SEM]), gender (56% women), BMI (24.5 ± 0.7 vs. 24.4 ± 0.7 kg/m² ), physical activity level, fasting plasma glucose and HbA1c. Patients with AD had a mean Eczema Area and Severity Index score of 8.5 ± 1.0 (moderate disease) and a mean AD duration of 28 ± 3 years. During the OGTT, circulating glucose, insulin, C-peptide, glucagon and glucose-dependent insulinotropic polypeptide, respectively, were similar in the two groups, except glucagon-like peptide-1, which was higher in patients with AD. The clamp showed no differences in insulin sensitivity between groups (M-value 9.2 ± 0.6 vs. 9.8 ± 0.8, P = .541, 95% CI -1.51; 2.60), or circulating insulin, C-peptide and glucagon levels.

CONCLUSIONS

Using OGTT and the hyperinsulinaemic euglycaemic clamp technique, we found no difference in insulin sensitivity or other gluco-metabolic characteristics between patients with mild to moderate AD and matched healthy controls, suggesting that the inflammatory skin disease AD has little or no influence on glucose metabolism.

Contact haptens in emollients marketed in two European countries (Poland and Spain)

INTRODUCTION AND OBJECTIVES

Atopic dermatitis (AD) is the most common skin disease among pediatric patients, which affects up to 20% of children worldwide. Characterized by pruritus and eczema, it is also associated with improper skin barrier function and allergen sensitization. Here, we aimed to assess the presence of haptens in emollients marketed in two European countries: in Poland and Spain, as, firstly, these products are considered to be AD's basic therapy, and, secondly, frequent application of potent sensitizers on atopic skin may result in contact dermatitis.

MATERIALS AND METHODS

We systematically searched for moisturizers explicitly described as "Atopic skin care" products in the most frequently visited online pharmacies in Poland and Spain. Subsequently, we created a database of all products and compared their composition with 139 contact haptens listed in the European Baseline Series (EBS), Fragrance and Cosmetic Series.

RESULTS

As of December 2018, our list comprised 159 and 111 emollients available on the Polish and Spanish markets, respectively. There were no ingredients listed in 28 (17.5%) products in Poland and 24 (21.6%) in Spain. Only 23 (17.5%) and 13 (14.8%) products were hapten free. The pattern of most common haptens was similar in both countries, including phenoxyethanol, tocopherol and tocopheryl acetate, undefined parfum in Poland and tocopherol, phenoxyethanol, tocopheryl acetate and undefined parfum in Spain.

CONCLUSIONS

This study shows that a vast majority of products taken into consideration contain at least one potential contact hapten. These findings indicate a need for patient education about potentially allergenic ingredients and stronger cooperation between academia and cosmetic manufacturers.

Topical corticosteroid vehicle composition and implications for clinical practice

This narrative review highlights the therapeutic significance of topical corticosteroid (TCS) vehicles and provides subsequent guidance to improve clinical and research outcomes. A greater understanding of the relationship between the topical vehicle, corticosteroid and skin is needed to ensure safer, more effective treatment for patients. Topical vehicles are not inert and can affect TCS bioavailability, due to the ability of their composition to positively or negatively influence skin status and change the physiochemical characteristics of an inherent corticosteroid. However, this principle is not commonly understood, and has contributed to inconsistencies in potency classification systems. This review provides an insight into the research methods and standardization needed to determine TCS product bioavailability. It identifies formulation components responsible for vehicle composition that underpin the quality, stability, compounding and functionalities of vehicle ingredients. This helps to contextualize how topical vehicles can be responsible for clinically significant effects, and how their composition gives products unique properties. In turn, this facilitates a more in-depth understanding of which resources offer information to inform the best selection of TCS products and why products should be prescribed by brand or manufacturer. This review will better equip clinicians and formulary teams to appraise products. It will also inform prescribing of Specials and why products should not be manipulated. The recommendations, accompanied by patient perspectives on using TCS products, assist clinical decision-making. They also identify the need for research into concomitant application of TCS products with other topical therapies.

Atopic dermatitis

Atopic dermatitis is a common inflammatory skin disorder characterised by recurrent eczematous lesions and intense itch. The disorder affects people of all ages and ethnicities, has a substantial psychosocial impact on patients and relatives, and is the leading cause of the global burden from skin disease. Atopic dermatitis is associated with increased risk of multiple comorbidities, including food allergy, asthma, allergic rhinitis, and mental health disorders. The pathophysiology is complex and involves a strong genetic predisposition, epidermal dysfunction, and T-cell driven inflammation. Although type-2 mechanisms are dominant, there is increasing evidence that the disorder involves multiple immune pathways. Currently, there is no cure, but increasing numbers of innovative and targeted therapies hold promise for achieving disease control, including in patients with recalcitrant disease. We summarise and discuss advances in our understanding of the disease and their implications for prevention, management, and future research.

Pediatric contact dermatitis: what's new

PURPOSE OF REVIEW

Allergic contact dermatitis (ACD) was once thought to be rare in children but recent studies have demonstrated that the prevalence of ACD is common and appears to be increasing in children. Current trends including toys, hobbies, and personal care products may play a role in potentially new allergen exposure or resurgence of certain allergens, making ACD a moving target in children.

RECENT FINDINGS

ACD and atopic dermatitis can coexist and certain clinical features can help differentiate ACD from endogenous atopic dermatitis in children. It is important to consider ACD in children with recalcitrant atopic dermatitis or dermatitis with atypical distribution. Patch testing has become a more common practice in children. In 2018, the first expert consensus-derived pediatric baseline series consisting of 38 allergens was proposed to aid in the diagnosis of ACD in children. Comparing recent patch testing data in the pediatric population, the top allergens ubiquitously identified were nickel, cobalt, neomycin, Myroxylon pereirae (balsam of Peru), fragrance mix I, fragrance mix II, methylisothiazolinone, methylchloroisothiazolinone/ methylisothiazolinone, formaldehyde, and lanolin.

SUMMARY

ACD is a common problem in children. Detection through patch testing, avoidance of offending allergens, and prevention of common allergens are the main focus of management of ACD in children.

Allergic Contact Dermatitis in Children: Recommendations for Patch Testing

PURPOSE OF REVIEW

Allergic contact dermatitis (ACD) affects 20% of children. However, diagnosis of ACD may be underreported in children due to lack of recognition. Patch testing is the gold standard for evaluation of ACD in children but poses unique challenges in this population.

RECENT FINDINGS

Recent studies highlight the significance of ACD and the utility of patch testing in children. Evaluation of ACD in children is difficult and requires knowledge of a child's exposure history, careful selection of allergens, and knowledge of specialized patch testing considerations to minimize irritation and maximize cooperation. Until recently, there were no agreed upon patch test series for children. In 2018, a comprehensive pediatric baseline series was published enabling thorough evaluation of ACD in children (Yu J, Atwater AR, Brod B, Chen JK, Chisolm SS, Cohen DE, et al. Dermatitis. 2018;29(4):206-12). This review provides an overview of the current literature, an update on pediatric ACD, and patch testing methods in children to effectively evaluate and manage ACD.

Behavior of 1-Deoxy-, 3-Deoxy- and N-Methyl-Ceramides in Skin Barrier Lipid Models

Ceramides (Cer) are essential components of the skin permeability barrier. To probe the role of Cer polar head groups involved in the interfacial hydrogen bonding, the N-lignoceroyl sphingosine polar head was modified by removing the hydroxyls in C-1 (1-deoxy-Cer) or C-3 positions (3-deoxy-Cer) and by N-methylation of amide group (N-Me-Cer). Multilamellar skin lipid models were prepared as equimolar mixtures of Cer, lignoceric acid and cholesterol, with 5 wt% cholesteryl sulfate. In the 1-deoxy-Cer-based models, the lipid species were separated into highly ordered domains (as found by X-ray diffraction and infrared spectroscopy) resulting in similar water loss but 4–5-fold higher permeability to model substances compared to control with natural Cer. In contrast, 3-deoxy-Cer did not change lipid chain order but promoted the formation of a well-organized structure with a 10.8 nm repeat period. Yet both lipid models comprising deoxy-Cer had similar permeabilities to all markers. N-Methylation of Cer decreased lipid chain order, led to phase separation, and improved cholesterol miscibility in the lipid membranes, resulting in 3-fold increased water loss and 10-fold increased permeability to model compounds compared to control. Thus, the C-1 and C-3 hydroxyls and amide group, which are common to all Cer subclasses, considerably affect lipid miscibility and chain order, formation of periodical nanostructures, and permeability of the skin barrier lipid models.

Twenty Clinically Pertinent Factors/Observations for Percutaneous Absorption in Humans

At least 20 clinically relevant factors affect percutaneous absorption of drugs and chemicals: relevant physico-chemical properties, vehicle/formulation, drug exposure conditions (dose, duration, surface area, exposure frequency), skin appendages (hair follicles, glands) as sub-anatomical pathways, skin application sites (regional variation in penetration), population variability (premature, infants, and aged), skin surface conditions (hydration, temperature, pH), skin health and integrity (trauma, skin diseases), substantivity and binding to different skin components, systemic distribution and systemic toxicity, stratum corneum exfoliation, washing-off and washing-in, rubbing/massaging, transfer to others (human to human and hard surface to human), volatility, metabolic biotransformation/cutaneous metabolism, photochemical transformation and photosensitivity, excretion pharmacokinetics, lateral spread, and chemical method of determining percutaneous absorption.

Effects of omega-O-acylceramide structures and concentrations in healthy and diseased skin barrier lipid membrane models

Ceramides (Cers) with ultralong (∼32-carbon) chains and ω-esterified linoleic acid, composing a subclass called omega-O-acylceramides (acylCers), are indispensable components of the skin barrier. Normal barriers typically contain acylCer concentrations of ∼10 mol%; diminished concentrations, along with altered or missing long periodicity lamellar phase (LPP), and increased permeability accompany an array of skin disorders, including atopic dermatitis, psoriasis, and ichthyoses. We developed model membranes to investigate the effects of the acylCer structure and concentration on skin lipid organization and permeability. The model membrane systems contained six to nine Cer subclasses as well as fatty acids, cholesterol, and cholesterol sulfate; acylCer content-namely, acylCers containing sphingosine (Cer EOS), dihydrosphingosine (Cer EOdS), and phytosphingosine (Cer EOP) ranged from zero to 30 mol%. Systems with normal physiologic concentrations of acylCer mixture mimicked the permeability and nanostructure of human skin lipids (with regard to LPP, chain order, and lateral packing). The models also showed that the sphingoid base in acylCer significantly affects the membrane architecture and permeability and that Cer EOP, notably, is a weaker barrier component than Cer EOS and Cer EOdS. Membranes with diminished or missing acylCers displayed some of the hallmarks of diseased skin lipid barriers (i.e., lack of LPP, less ordered lipids, less orthorhombic chain packing, and increased permeability). These results could inform the rational design of new and improved strategies for the barrier-targeted treatment of skin diseases.

Staphylococcal Virulence Factors on the Skin of Atopic Dermatitis Patients

For the first time, we show that secreted staphylococcal virulence factors can be quantified at the protein level directly from skin swabs obtained from the skin of atopic dermatitis patients. This technique eliminates the need to culture Staphylococcus aureus and then test the strain’s potential to produce secreted virulence factors. Our methodology shows that secreted virulence factors are present on the skin of atopic patients and provides a more accurate means of evaluating the physiological impact of S. aureus in inflammatory diseases such as atopic dermatitis.

Staphylococcus aureus is the leading cause of skin and soft tissue infections, bacteremia, infective endocarditis, osteoarticular, pleuropulmonary, and device-related infections. Virulence factors secreted by S. aureus, including superantigens and cytotoxins, play significant roles in driving disease. The ability to identify virulence factors present at the site of infection will be an important tool in better identifying and understanding how specific virulence factors contribute to disease. Previously, virulence factor production has been determined by culturing S. aureus isolates and detecting the mRNA of specific virulence factors. We demonstrated for the first time that virulence factors can be directly detected at the protein level from human samples, removing the need to first culture isolated bacteria. Superantigens and cytotoxins were detected and quantified with a Western dot blot assay by using reconstituted skin swabs obtained from patients with atopic dermatitis. This methodology will significantly enhance our ability to investigate the complex host-microbe environment and the effects various therapies have on virulence factor production. Overall, the ability to directly quantify virulence factors present at the site of infection or colonization will enhance our understanding of S. aureus-related diseases and help identify optimal treatments.

IMPORTANCE For the first time, we show that secreted staphylococcal virulence factors can be quantified at the protein level directly from skin swabs obtained from the skin of atopic dermatitis patients. This technique eliminates the need to culture Staphylococcus aureus and then test the strain’s potential to produce secreted virulence factors. Our methodology shows that secreted virulence factors are present on the skin of atopic patients and provides a more accurate means of evaluating the physiological impact of S. aureus in inflammatory diseases such as atopic dermatitis.