Irritant contact dermatitis: A review

'Eczematous' dermatitis of the nipple: clinical and histopathological differential diagnosis of Paget disease

The nipple can be affected by many malignant and benign entities. A wide variety of diseases including Paget disease, atopic dermatitis and nipple candidiasis can cause eczema-like changes in the nipple. In cases of diagnostic uncertainty, tissue sampling may be indicated. A true eczematous lesion, such as atopic dermatitis, typically shows a spongiotic dermatitis pattern. Paget disease, on the other hand, presents with infiltration of the nipple epidermis by neoplastic cells. The presence of atypical cells scattered in the epidermis in a pagetoid pattern opens up a histopathological differential diagnosis encompassing squamous cell carcinoma in situ and malignant melanoma, among others. Immunohistochemistry is commonly used to render a diagnosis. The objective of this article is to discuss Paget disease and highlight relevant clinical and histopathological differential diagnoses.

Humulus japonicus ameliorates irritant contact dermatitis by suppressing NF‑κB p65‑dependent inflammatory responses in mice

As a type of contact dermatitis (CD), irritant CD (ICD) is an acute skin inflammation caused by external irritants, such as soap, water and chemicals. Humulus japonicus (HJ) is a herbal medicine widely distributed in Asian countries and has anti-inflammatory, antimicrobial and antioxidant effects. The current study aimed to investigate the anti-dermatitis effect of HJ on ICD and determine the molecular basis of this effect using 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced dermatitis mice models and lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Mice were orally administered HJ and luteolin, the major compound in HJ, and topically administered TPA on the right ear to induce dermatitis. Topical application of TPA induced ear redness, oedema and increased infiltration of neutrophils and macrophages, which ameliorated following HJ and luteolin administration. The gene expression levels of inflammatory cell migrating chemokines, chemokine ligand 3 (CCL3) and chemokine (C-X-C motif) ligand 2 (CXCL2), and pro-inflammatory cytokine, IL-1β, were reduced in the ears of HJ- and luteolin-treated mice. HJ and luteolin also inhibited the gene expression of chemokines, CCL3 and CXCL2, and pro-inflammatory cytokines, IL-1β, IL-6 and TNF-α, in LPS-stimulated RAW264.7 cells. Moreover, HJ and luteolin decreased the expression levels of two key inflammatory enzymes, cyclooxygenase-2 (COX2) and inducible nitric oxide synthase (iNOS), and total and active phosphorylation of NF-κB p65. These results suggest that HJ could have a protective effect against ICD by suppressing inflammatory responses; therefore, HJ is a promising therapeutic strategy for ICD treatment.

Emerging nanotechnology backed formulations for the management of atopic dermatitis

Atopic dermatitis is a prevalent chronic skin inflammation affecting 2.1 to 4.1% of adults globally. The complexity of its pathogenesis and the relapsing nature make it challenging to treat. Current treatments follow European Academy of Dermatology and Venerology guidelines, but advanced cases with recurring lesions lack effective therapies. To address this gap, researchers are exploring nanotechnology for targeted drug delivery. Nanoparticles offer benefits such as improved drug retention, stability, controlled release and targeted delivery through the disrupted epidermal barrier. This integrated review evaluates the current state of AD treatment and highlights the potential of novel nano-formulations as a promising approach to address the disease.

Advancing the understanding of allergic contact dermatitis: from pathophysiology to novel therapeutic approaches

Allergic contact dermatitis (ACD) is a common inflammatory skin disease that, especially when the condition becomes chronic, has a high impact on the quality of life and represents a significant disease burden. ACD represents a type IV delayed-type hypersensitivity reaction that is triggered by contact with an allergen in previously sensitized individuals through the activation of allergen-specific T cells. In the acute phase, it is characterized by eczematous dermatitis, which presents with erythema, edema, vesicles, scaling, and intense itch. Non-eczematous clinical forms are also described (lichenoid, bullous, and lymphomatosis). Lichenification is the most common clinical picture in the chronic phase if the culprit allergen is not found or eliminated. ACD can be associated with both occupational and non-occupational exposure to allergens, representing approximately 90% of occupational skin disorders along with irritant contact dermatitis. Patch testing with suspected allergens is required for a diagnosis. Metals, especially nickel, fragrance mix, isothiazolinones, and para-phenylenediamine, are the most commonly positive allergens in patients patch tested for suspected ACD. The treatment goal is to avoid contact with the culprit agent and use topical and/or systemic corticosteroid therapy.

Occupational Skin Dermatitis among Healthcare Workers Associated with the COVID-19 Pandemic: A Review of the Literature

The skin is the outermost layer of the human body and is continually exposed to numerous external stimuli, which can cause unwanted skin irritation. Occupational skin diseases are the most prevalent form of work-related illness and are found in a variety of sectors, particularly healthcare. During the recent COVID-19 pandemic, healthcare professionals experienced a variety of unexpected, unusual occupational skin diseases associated with COVID-19-engaged employment. Because the clinical characteristics of these types of skin inflammation are unique, this review focuses on the characteristics of a large category of occupational workers, namely COVID-19-engaged healthcare professionals. Furthermore, we examined the potential pathogeneses of occupational skin disorders associated with COVID-19-engaged labor, as well as different preventative methods.

Relevant Dermatoses Among U.S. Military Service Members: An Operational Review of Management Strategies and Telemedicine Utilization

Despite skin being the largest and most exposed organ of the human body, skin issues can be challenging to diagnose in deployed military service members. Common reasons deployed soldiers seek dermatological evaluation include infections, inflammatory skin conditions, and skin growth. Due to limited access to specialized care in deployed settings, dermatological conditions are undertreated and underdiagnosed. As a result, dermatological conditions are a leading contributor to decreased combat effectiveness among deployed medical forces. To lessen the burden of dermatological diseases, military providers should promptly identify operational skin diseases and alleviate modifiable barriers faced by service members. In a post-pandemic era with novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and monkeypox infections, the duty to effectively treat operational skin lesions is ever important. The need for military dermatologists continues to rise as the global landscape continues to evolve with unprecedented infections and increased bioterrorism threats. Teledermatology offers many solutions to mitigate the high demand for dermatologists during pandemics. Dermatological consultations account for the highest number of telemedicine visits in the US Military Health System (MHS). As such, increased utilization of teledermatology will reduce infection-related dermatological sequelae and prevent the medical evacuation of service members from military operations. This review collates and categorizes relevant dermatological conditions encountered among deployed personnel. This report outlines the standard of care and modified treatments recommended according to potential barriers faced in operational settings.

Anti-Inflammatory and Antioxidant Properties of Physalis alkekengi L. Extracts In Vitro and In Vivo: Potential Application for Skin Care

OBJECTIVE

Inflammatory skin disorders are becoming major issues threatening public health with increasing prevalence. This study was to evaluate the anti-inflammatory, antioxidant, and antisenescent activities of traditional folk medicinal plant, Physalis alkekengi L. extracts to alleviate skin inflammation and its possible mechanisms.

METHODS

Lipopolysaccharides (LPS)-treated murine macrophages RAW264.7 and human skin keratinocytes HaCaT were incubated with the plant extracts, respectively. The production of nitric oxide (NO) was tested by using Griess reagents. The activity of nitric oxide synthase (NOS) was detected through a fluorescence microplate reader. Reactive oxygen species (ROS) production and cell apoptosis were quantified by flow cytometry. The proinflammatory cytokines were measured using ELISA and qRT-PCR. Human skin fibroblasts (HFF-1) were coincubated with D-galactose (D-gal) and the plant extracts. The senescence associated-galactosidase (SA-β-gal) was stained to evaluate cellular senescence. The senescence-associated secretory phenotype (SASP), IL-1β, was measured through ELISA. The mRNA of IL-1α in SLS-stimulated and PGE2 in UV-radiated 3D skin models were detected by qRT-PCR. In vivo ROS production and neutrophil recruitment in CuSO₄-treated zebrafish models were observed by fluorescence microscopy. Inflammation-related factors were measured by qRT-PCR. Results. In vitro, Physalis alkekengi L. significantly reduced NO production, NOS activity, cell apoptosis, transcription of TNF-α, IL-6, IL-1β and ROS production. These plant extracts markedly attenuated SA-β-gal and IL-1β and downregulated the production of IL-1α and PGE2. In vivo, the plant extracts dramatically dampened ROS production, the number of neutrophils, and proinflammatory cytokines.

CONCLUSIONS

Cumulatively, this work systematically demonstrated the anti-inflammatory, antioxidant, and antisenescent properties of Physalis alkekengi L. and proposed the possible roles of Physalis alkekengi L. in inflammatory signaling pathways, providing an effective natural product for the treatment of inflammatory skin disorders.

Irritant Contact Dermatitis — a Review

Purpose of Review

Recent Findings

Summary

Determination of potentially toxic metals in depilatory products in the Iranian markets: human health risk assessment

This study aimed to investigate the concentrations of heavy metals, including lead (Pb), cadmium (Cd), chromium (Cr), zinc (Zn), cobalt (Co), and arsenic metalloid (As), to assess their health risks in the popular depilatory products of the Iranian markets. Twenty-one samples of 7 popular brands of depilatory products, inclusive of cream and powder, were examined. Selected elements were measured by inductively coupled plasma optical emission spectrometry (ICP-OES) using the appropriate procedure for acid digestion and the measurement of heavy metal contents. The differences in heavy metal concentrations were investigated according to the type of product, brand, country of production, and product price using t test and one-way analysis of variance and post hoc Tukey test. Finally, carcinogenic and non-carcinogenic risk assessments were calculated for the studied elements. The results showed that Pb (5.46±2.30 mg/kg) and Co (0.16±0.69 mg/kg) had the highest and lowest concentrations in these products, respectively. In general, the concentration of heavy metals in depilatory creams was less than the concentration of elements in depilatory powders and less than the maximum allowable limits as defined by the Institute of Standards and Industrial Research of Iran (ISIRI). There was a direct and significant relationship between the concentration of heavy metals in depilatory powders and the product's price. Moreover, the amount of As in one of the brands of depilatory powder was determined to exceed the standard value (2 mg/kg). Also, hazard index (HI) and lifetime cancer risk (LCR) were below 1 and 10^-6, respectively, which indicated that this mentioned heavy metal had no probable non-carcinogenic and carcinogenic risks for consumers. According to this study, it was evident that the chances of cancer and non-cancer risk using depilatory products were unlikely, but continuous use can be harmful due to the excessive accumulation of these heavy metals.

Causes of irritant contact dermatitis after occupational skin exposure: a systematic review

PURPOSE

Irritant contact dermatitis (ICD) is a major cause of occupational disease. The aim was to review the relation between exposure to occupational irritants and ICD and the prognosis of ICD.

METHODS

Through a systematic search, 1516 titles were identified, and 48 studies were included in the systematic review.

RESULTS

We found that the evidence for an association between ICD and occupational irritants was strong for wet work, moderate for detergents and non-alcoholic disinfectants, and strong for a combination. The highest quality studies provided limited evidence for an association with use of occlusive gloves without other exposures and moderate evidence with simultaneous exposure to other wet work irritants. The evidence for an association between minor ICD and exposure to metalworking fluids was moderate. Regarding mechanical exposures, the literature was scarce and the evidence limited. We found that the prognosis for complete healing of ICD is poor, but improves after decrease of exposure through change of occupation or work tasks. There was no substantial evidence for an influence of gender, age, or household exposures. Inclusion of atopic dermatitis in the analysis did not alter the risk of ICD. Studies were at risk of bias, mainly due to selection and misclassification of exposure and outcome. This may have attenuated the results.

CONCLUSION

This review reports strong evidence for an association between ICD and a combination of exposure to wet work and non-alcoholic disinfectants, moderate for metalworking fluids, limited for mechanical and glove exposure, and a strong evidence for a poor prognosis of ICD.

CCL2‒CCR2 Signaling in the Skin Drives Surfactant-Induced Irritant Contact Dermatitis through IL-1β‒Mediated Neutrophil Accumulation

Surfactant-induced cumulative irritant contact dermatitis (ICD) is a common and clinically important skin disorder. CCL2 is known to mediate inflammation after tissue damage in various organs. Thus, we investigated whether and how CCL2 contributes to the development of murine cumulative ICD induced by a common surfactant, SDS. Wild-type mice treated topically with SDS for 6 consecutive days developed skin inflammation that recapitulated the features of human cumulative ICD, including barrier disruption, epidermal thickening, and neutrophil accumulation. CCL2 was upregulated in SDS-treated skin, and local CCL2 blockade attenuated SDS-induced ICD. SDS-induced ICD and neutrophil accumulation were also attenuated in mice deficient in CCR2, the receptor for CCL2. Neutrophil depletion alleviated SDS-induced ICD, suggesting that impaired neutrophil accumulation was responsible for the amelioration of ICD in CCR2-deficient mice. In RNA-sequencing analyses of SDS-treated skin, the expression levels of Il1b in Ccr2-deficient mice were highly downregulated compared with those in wild-type mice. Furthermore, the intradermal administration of IL-1β in the SDS-treated skin of CCR2-deficient mice restored the local accumulation of neutrophils and the development of ICD. Collectively, our results suggest that CCL2‒CCR2 signaling in the skin critically promotes the development of SDS-induced ICD by inducing IL-1β expression for neutrophil accumulation.

The History of Surfactants and Review of Their Allergic and Irritant Properties

Surfactants, many of which are used as detergents, can be found in many common household items, such as shampoos, conditioners, soaps, and cosmetics. One should recognize the multitude of surfactants that are used in today's products to identify any potential allergic contact dermatitis (ACD) or irritant contact dermatitis (ICD). Given their abundance in everyday products, it is understandable that many cases of occupational contact dermatitis that arise can be attributed to surfactants. The products most connected with ACD are cocamidopropyl betaine, oleamidopropyl dimethylamine, decyl glucoside, 3-dimethylaminopropylamine, amidoamine, and cocamide diethanolamine. Similarly, the most common surfactant-related causes of ICD are sodium lauryl sulfate and benzalkonium chloride. It is important for dermatologists to identify the causes and differentiate between the two, to adjust treatments and products accordingly. Here, the most frequently used surfactants, as well as their correlation between ACD and ICD, will be reviewed.

What Is New in Occupational Allergic Contact Dermatitis in the Year of the COVID Pandemic?

Purpose of Review

This article aims to summarize some recent trends in occupational allergic contact dermatitis (ACD), including dermatitis related to pandemic-level personal protective equipment in healthcare workers, hazards patients may experience when working from home, and occupational perspectives on the recent American Contact Dermatitis Society (ACDS) allergens of the year and ACDS Core Allergen Series updates.

Recent Findings

Recent ACDS Allergens of the Year may be particularly relevant to healthcare workers, including isobornyl acrylate, which is present in glucose sensors and propylene glycol present in hand cleansers and disinfectants. Lavender, limonene, and linalool, all of which are new additions to the ACDS Core Allergen Series, have been reported as causes for occupational ACD in massage therapists and aromatherapists. Isothiazolinone allergy continues to rise in both consumer and occupational settings. Finally, the COVID-19 pandemic has resulted in a wave of occupational ACD in healthcare workers to personal protective equipment, and revealed new potential allergens for individuals working from home.

Summary

Occupational allergic contact dermatitis continues to exert a significant occupational disease burden. Remaining aware of the current trends in allergens may allow for earlier recognition, diagnosis, and treatment, subsequently helping our patients to work in healthier and safer environments.

Machine-learning-driven biomarker discovery for the discrimination between allergic and irritant contact dermatitis

Contact dermatitis tremendously impacts the quality of life of suffering patients. Currently, diagnostic regimes rely on allergy testing, exposure specification, and follow-up visits; however, distinguishing the clinical phenotype of irritant and allergic contact dermatitis remains challenging. Employing integrative transcriptomic analysis and machine-learning approaches, we aimed to decipher disease-related signature genes to find suitable sets of biomarkers. A total of 89 positive patch-test reaction biopsies against four contact allergens and two irritants were analyzed via microarray. Coexpression network analysis and Random Forest classification were used to discover potential biomarkers and selected biomarker models were validated in an independent patient group. Differential gene-expression analysis identified major gene-expression changes depending on the stimulus. Random Forest classification identified CD47, BATF, FASLG, RGS16, SYNPO, SELE, PTPN7, WARS, PRC1, EXO1, RRM2, PBK, RAD54L, KIFC1, SPC25, PKMYT, HISTH1A, TPX2, DLGAP5, TPX2, CH25H, and IL37 as potential biomarkers to distinguish allergic and irritant contact dermatitis in human skin. Validation experiments and prediction performances on external testing datasets demonstrated potential applicability of the identified biomarker models in the clinic. Capitalizing on this knowledge, novel diagnostic tools can be developed to guide clinical diagnosis of contact allergies.

Mechanical Irritation in Vascularized Composite Tissue Allotransplantation Triggers Localized Skin Rejection

BACKGROUND

Mechanical and thermal stress has been observed to trigger skin rejection in hand-transplanted patients. This study aims to investigate this phenomenon.

METHODS

Syngeneic and allogeneic orthotopic hindlimb transplantations were performed using male rats (Brown Norway to Lewis). Using a specially designed device, standardized mechanical skin irritation at a force of 5 N was applied to the planta pedis of the transplanted limb for 10 days, 4 times daily for 10 minutes. Biopsies, taken on day 10 and after a 5-day observational period, were assessed for macroscopic alterations using a standardized scale, by histopathology and immunohistochemistry, and for inflammatory protein expression using Luminex technology.

RESULTS

Allogeneic animals displayed significant aggravated macroscopic skin alterations compared with naive (P < 0.0001) and syngeneic controls (P = 0.0023). Histopathology showed a trend toward higher rejection/inflammation grades in allogeneic animals compared with syngeneic controls. Minor skin alterations in syngeneic limbs recovered quickly; however, in allogeneic limbs, macroscopic skin alterations were significantly more pronounced (P < 0.0001) 5 days after irritation. Interleukin-1b and interferon-γ levels were upregulated in skin of allogeneic limbs.

CONCLUSIONS

Mechanical skin irritation in vascularized composite allotransplantation can trigger localized skin inflammation consistent with rejection.

Efficacy of oral supplementation of whey protein in patients with contact dermatitis: A pilot randomized double-blind placebo-controlled clinical trial

Whey protein is a popular dietary product that has numerous health benefits such as immune modulation. In this study, we assessed efficacy of whey protein in management of patients with contact dermatitis (CD) through a double blind, randomized controlled clinical trial in Emam Reza clinic, Shiraz, Iran. Twenty-five patients in each group were randomly assigned to receive whey protein or placebo powder, 30 g in 200 mL warm water at fasting time for 4 weeks. Outcome measures were Dermatology Life Quality Index (DLQI) questionnaire and the Eczema Area and Severity Index (EASI) score. Furthermore, subjective total improvement (assessed by visual analogue scale) was set as the other primary outcome measure. A significant decrease was observed in the scores of EASI, DLQI, and subjective total improvement in the drug group after the intervention compared with the baseline. However, no changes were seen in the placebo group. Moreover, there was a significant reduction in the scores of EASI (P = .002) and subjective total improvement scores (P = .039) over the study period in the drug group compared with the placebo group. According to the results of this study, it seems that oral supplementation of whey protein could improve the symptoms of CD compared with placebo.

Scratching the Surface: A Review of Dermatitis

GENERAL PURPOSE

To present a case-based review illustrating atopic and contact dermatitis, including management of these conditions using topical and systemic therapies.

TARGET AUDIENCE

This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care.

LEARNING OBJECTIVES/OUTCOMES

After participating in this educational activity, the participant should be better able to:1. Review the prevalence, etiology, and consequences of the various types of dermatitis.2. Describe the clinical manifestations and differential diagnosis of the various types of dermatitis.3. Outline the treatment options for the various types of dermatitis.

ABSTRACT

Eczematous reactions such as atopic dermatitis and contact dermatitis are prevalent worldwide. Despite contrasting pathophysiology, the diagnosis and management of these dermatitides can be challenging for healthcare providers. Differences in the distribution of the affected areas, duration of onset, and associated symptoms may help to distinguish these conditions. Diagnosis of the respective conditions is useful in developing appropriate management plans. Herein, the authors present a case-based review illustrating these different disease entities. Management of these conditions, including the use of topical and systemic therapies, is discussed.

IL-6 Negatively Regulates IL-22Rα Expression on Epidermal Keratinocytes: Implications for Irritant Contact Dermatitis

Irritant Contact Dermatitis (ICD) is characterized by epidermal hyperplasia and inflammatory cytokine release. IL-6 has been shown to be involved in the pathogenesis of ICD; however, the involvement of the IL-22/IL-22Rα axis and its relation to IL-6 in the inflammatory response following irritant exposure are unknown. Using a chemical model of ICD, it was observed that mice with a keratinocyte-specific knockout of IL-6Rα (IL-6Rα^Δker) presented with increased inflammation and IL-22Rα and IL-22 protein expression relative to WT following irritant exposure, indicating that IL-6Rα deficiency in epidermal keratinocytes leads to the upregulation of IL-22Rα and its ligand during ICD. Furthermore, it was shown that IL-6 negatively regulates the expression of IL-22Rα on epidermal keratinocytes. This effect is functional as the effects of IL-22 on keratinocyte proliferation and differentiation were markedly reduced when keratinocytes were pretreated with IL-6 prior to IL-22 treatment. These results show that IL-6 modulates the IL-22/IL-22Rα axis in the skin and suggest that this occurrence may be associated with the increased epidermal hyperplasia and exacerbated inflammatory response observed in IL-6Rα^Δker mice during ICD.

Keratinocyte-specific deletion of the IL-6RΑ exacerbates the inflammatory response during irritant contact dermatitis

Irritant Contact Dermatitis (ICD) is the most common occupational skin disorder. During ICD, keratinocytes initiate the inflammatory cascade by producing cytokines including IL-6. This laboratory previously reported that IL-6 deficiency exacerbates skin inflammation during ICD, yet the role of the IL-6Rα in keratinocyte function has yet to be elucidated. To investigate how IL-6Rα function in keratinocytes influences the inflammatory response during ICD, keratinocyte-specific IL-6Rα KO (IL6ra^Δker) and WT mice were exposed to two well-known occupational irritants; JP-8 jet fuel, and benzalkonium chloride (BKC), or acetone control for three days. Dermatitis lesions were collected and flow cytometric and immunohistochemical analyses revealed that IL6ra^Δker skin displayed increased populations of CD11b⁺CD45⁺ and F4/80⁺ cells respectively relative to WT. However, IL6ra^Δker mouse skin contained reduced numbers of γδ T cells relative to WT. Furthermore, IL6ra^Δker skin expressed increased levels of pro-inflammatory cytokines including IL-1β, IL-22, and CCL4 but decreased levels of anti-inflammatory cytokines IL-4 and IL-10. These results indicate that epidermal keratinocyte IL-6Rα function modulates epidermal hyperplasia, immune cell infiltration into skin and cytokine expression during ICD and suggests that the previously reported protective effect of IL-6 during ICD might be mediated primarily by keratinocyte derived IL-6Rα.

Asteraceae species as potential environmental factors of allergy

The statistics from Europe and the USA have proven a high risk for skin diseases associated with plant contact. Therefore, plant-induced dermatitis is of increasing attention in dermatology. The focus of this paper was to present the current knowledge on aspects of contact allergy related to Asteraceae (Compositae) species. The Asteraceae family is one of the largest in the world with members across all continents. The PubMed/Medline databases have been searched. The Asteraceae representatives consist of diverse secondary metabolites, which exhibit various advantageous effects in humans. In particular, sesquiterpene lactones (SLs) may cause sensitization resulting in skin irritation and inflammation. In this study, we tried to reveal the allergenic potential of several Asteraceae species. The Asteraceae-related allergy symptoms involve eczema, hay fever, asthma, or even anaphylaxis. Furthermore, the evidence of severe cross-reactivity with food and pollen allergens (PFS) in patients sensitive to Asteraceae allergens have been announced. Further identification and characterization of secondary metabolites and possible allergens in Asteraceae are necessary for the better understanding of Asteraceae-related immune response. The Asteraceae allergy screening panel (the SL mix and the Compositae mix of five plant species) is a promising tool to improve allergy diagnostics and therapy.

Cariniana domestica fruit peels present topical anti-inflammatory efficacy in a mouse model of skin inflammation

To investigate the topical anti-inflammatory activity of the crude extract of Cariniana domestica fruit peels (CdE), its dichloromethane, n-butanol, and ethyl acetate (EtAc) fractions, and steroids (β-sitosterol, lupeol, and stigmasterol) isolated from the EtAc fraction in models of irritant contact dermatitis (ICD) croton oil-induced in mice. We induced skin inflammation by single (acute; 1 mg/ear) and multiple (chronic; 0.4 mg/ear) croton oil application. We topically applied C. domestica (CdE, fractions, and gel formulations) and β-sitosterol, lupeol, and stigmasterol immediately after applying croton oil. HPLC-DAD chromatography of the EtAc fraction and stability of the gel formulations were verified. HPLC-DAD of the EtAc fraction revealed the stigmasterol, lupeol, and β-sitosterol presence. CdE and EtAc fraction gels showed no organoleptic or pH changes at room temperatures. CdE and dichloromethane, n-butanol, and EtAc (1 mg/ear) fractions decreased the acute ear edema with maximum inhibition (I_max) of 97 ± 2, 86 ± 1, 81 ± 4, and 95 ± 2%, respectively. CdE and EtAc fraction gel presented similar effects, with respective I_max of 85 ± 6% (3%;15 mg/ear) and 82 ± 2% (1%;15 mg/ear). β-sitosterol (7.5 μg/ear), lupeol (10 μg/ear), and stigmasterol (5.7 μg/ear) also reduced this parameter by 46 ± 8, 51 ± 7, and 62 ± 7%, respectively. All topical treatments reduced the inflammatory cells' infiltration in the acute ICD model. CdE reduced the ear edema by 77 ± 4% (1 mg/ear) and the inflammatory cell infiltration in the chronic ICD model. CdE's anti-inflammatory effect was accompanied by a minimum development of adverse effects. C. domestica demonstrates a promising potential for the development of a topical anti-inflammatory agent. Graphical abstract Cariniana domestica, popularly known as jequitibá-roxo, presented topical anti-inflammatory activity in an acute and chronic irritant contact dermatitis croton oil-induced in mice. The crude extract (solutions and gel formulations) and different fractions obtained from fruit peels of C. domestica showed topical antiinflammatory activity on skin inflammation models with minimum adverse effects in preliminary toxicological studies (behavior and biochemical parameters). Moreover, the HPLC analysis revealed the presence of β-sitosterol, stigmasterol and lupeol, which also presented topical anti-inflammatory effect in the acute irritant contact dermatitis croton oil-induced. Our findings support the use of this species as a promising topical antiinflammatory agent.

The Role and Diagnosis of Allergic Contact Dermatitis in Patients with Atopic Dermatitis

Patients with atopic dermatitis (AD) have increased penetration of allergens, immune dysregulation (including shared cytokine pathways), and frequent use of emollients and topical medications, all of which may predispose toward developing allergic contact dermatitis (ACD). Recent systematic reviews have suggested that ACD is a significant clinical problem in both children and adults with AD. While this remains controversial, ACD remains an important comorbidity and potential exacerbant of AD in clinical practice. Common relevant allergens, include lanolin, neomycin, formaldehyde, sesquiterpene lactone mix, compositae mix, and fragrances that are commonly found in AD patients' personal care products. We herein review the clinical scenarios where patch testing is indicated in AD. In addition, we review the contraindications, preferred patch-testing series, pitfalls, and challenges determining the relevance of positive patch-test reactions in AD patients.

Interactions between surfactants and the skin - Theory and practice

One of the primary causes of skin irritation is the use of body wash cosmetics and household chemicals, since they are in direct contact with the skin, and they are widely available and frequently used. The main ingredients of products of this type are surfactants, which may have diverse effects on the skin. The skin irritation potential of surfactants is determined by their chemical and physical properties resulting from their structure, and specific interactions with the skin. Surfactants are capable of interacting both with proteins and lipids in the stratum corneum. By penetrating through this layer, surfactants are also able to affect living cells in deeper regions of the skin. Further skin penetration may result in damage to cell membranes and structural components of keratinocytes, releasing proinflammatory mediators. By causing irreversible changes in cell structure, surfactants can often lead to their death. The paper presents a critical review of literature on the effects of surfactants on the skin. Aspects discussed in the paper include the skin irritation potential of surfactants, mechanisms underlying interactions between compounds of this type and the skin which have been proposed over the years, and verified methods of reducing the skin irritation potential of surfactant compounds. Basic research conducted in this field over many years translate into practical applications of surfactants in the cosmetic and household chemical industries. This aspect is also emphasized in the present study.

Anti-pruritic and anti-inflammatory effects of oxymatrine in a mouse model of allergic contact dermatitis

BACKGROUND

Allergic contact dermatitis (ACD) is a highly prevalent inflammatory disease of the skin. As a result of the complex etiology in ACD, therapeutic compounds targeting refractory pruritus in ACD lack efficacy and lead to numerous side effects.

OBJECTIVE

In this study, we investigated the anti-pruritic effects of oxymatrine (OMT) and explored its mechanism of action in a mouse model of ACD.

METHOD

72 male SPF C57BL/6 mice were randomly divided into control group, ACD model group, dexamethasone positive control group (0.08 mg kg-1) and 3 OMT groups (80, 40, 20 mg kg-1). OMT was administrated by intraperitoneal injection 1 h before video recording on day 10, 24 h after 2nd challenge with SADBE. Cheek skin fold thickness was measured before treatment and after recording. H&E staining was used for pathological observation. RT-qPCR, Immunohistochemistry and LEGENDplexTM assay were used to detect cytokines levels. The population of Treg cells in peripheral blood were detected via flow cytometry.

RESULTS

OMT treatment significantly decreases the skin inflammation and scratching bouts. It rescues defects in epidermal keratinization and inflammatory cell infiltration in ACD mice. Administration of OMT significantly reduced levels of IFN-γ, IL-13, IL-17A, TNF-α, IL-22 and mRNA expression of TNF-α and IL-1β. Furthermore, it increased the percentage of Treg cells in peripheral blood of ACD mice.

CONCLUSION

We have demonstrated that OMT exhibits anti-pruritic and anti-inflammatory effects in ACD mice by regulating inflammatory mediators. OMT might emerge as a potential drug for the treatment of pruritus and skin inflammation in the setting of ACD.

Skin targeting of resveratrol utilizing solid lipid nanoparticle-engrossed gel for chemically induced irritant contact dermatitis

Irritant contact dermatitis (ICD) is a chronic and relapsing skin disease with severe eczematous lesions. Despite its growing prevalence, therapeutic treatments remain limited. Long-term topical corticosteroid treatment can induce skin atrophy, hypopigmentation, and increase in transepidermal water loss. An innovative dermal treatment is essential to reduce the side effects of corticosteroids. Topical resveratrol (RES), although effective for ICD, is a challenging molecule due to low solubility and poor bioavailability. The objective of this work was to build RES-loaded solid lipid nanoparticles (RES-SLNs) with skin targeting. For this purpose, RES-SLNs were prepared using the probe ultrasonication method utilizing Precirol ATO 5 and Tween 20. The RES-SLNs were evaluated for particle size, entrapment efficiency (EE), and transmission electron microscopy (TEM) studies. Further, RES-SLNs were incorporated into Carbopol gel and investigated for ex vivo skin permeation, deposition study on human cadaver skin, and finally skin irritation study on New Zealand White rabbits. It was further assessed for possible beneficial effects on ICD using BALB/c mice. RES-SLN showed mean size below 100 nm and 68-89% EE. TEM studies confirmed spherical particles in the nanometer range. An ex vivo study of RES-SLN-loaded gel exhibited controlled drug release up to 24 h; similarly, in vitro drug deposition studies showed potential of skin targeting with no skin irritation. RES-SLN gel confirmed competent suppression of ear swelling and reduction in skin water content in the BALB/c mouse model of ICD when compared to marketed gel. Thus, the formulated RES-SLN gel would be a safe and effective alternative to conventional vehicles for treatment of ICD.

Skin targeting of curcumin solid lipid nanoparticles-engrossed topical gel for the treatment of pigmentation and irritant contact dermatitis

Irritant contact dermatitis (ICD) and hyperpigmentation are the problems associated with skin. Topical curcumin (CUR) although effective in hyperpigmentation and ICD, is a challenging molecule due to low-solubility. Encapsulation of CUR into solid lipid nanoparticles (SLNs) makes it amenable to topical dosing as their small size promotes its penetration into the skin. CUR-SLNs were prepared using Precirol ATO5 and Tween-80 by probe ultrasonication method. Further, CUR-SLNs were incorporated into Carbopol gel and investigated for ex-vivo skin permeation, skin deposition and skin irritation studies. The potential of CUR-SLN gel was checked against hyperpigmentation through the inhibition of tyrosinase enzyme. It was further evaluated for possible effects on ICD using BALB/c mice. The optimized CUR-SLN showed the particle size of 51 nm and 93% EE. Ex vivo permeation of CUR-SLN gel exhibited controlled drug release up to 24 h, similarly in vitro drug deposition studies showed potential for skin targeting. In vitro tyrosinase inhibition assay indicates that the formulated gel has potential in skin depigmentation. The gel also confirmed proficient suppression of ear swelling and reduction in skin water content in the BALB/c mouse. Thus, the CUR-SLN gel would be a safe and effective alternative to conventional vehicles for treatment of ICD and pigmentation.

Determination of some heavy metals in selected cosmetic products sold in kano metropolis, Nigeria

The study was aimed at assessing the levels of some toxic metals in different cosmetic products sold at different shopping malls and markets in Kano Metropolis. The cosmetic items included ten face powder, ten skin lightening creams and ten lipsticks of various prices. The cosmetics were digested and analyzed for heavy metals (manganese, nickel, copper, cadmium, chromium and lead) using atomic absorption spectrophotometer. The range of the concentrations in skin lightening creams is 4.90-24.51, 3.68-11.03, 4.24-8.48, 0.14-1.32, 0-0.05 and 0.05-0.14 mg kg-1 for Mn, Ni, Cu, Cd, Cr and Pb respectively. The range in face powders are 4.90-44.12, 3.68-11.03, 4.24-8.48, 0.07-1.74, 0-0.03 and 0.08-0.33 mg kg-1 for Mn, Ni, Cu, Cd, Cr and Pb respectively. The concentration ranges in lipsticks are 2.45-22.06, 0-11.03, 4.24-12.71, 0.07-1.67, 0-0.05 and 0-0.19 mg kg-1 for Mn, Ni, Cu, Cd, Cr and Pb respectively. T test showed no statistical significant difference in concentrations of metals between the expensive and cheap cosmetic products. It is obvious from the present study that the use of these cosmetic products exposes users to low concentrations of toxic heavy metals which could constitute potential health risk to users since they are known to accumulate in biological systems over time. Similarly, regular monitoring of other heavy metals and chemicals used in the manufacture of cosmetics products which may cause health risks to users should be emphasized.

The Scourge of the Spurge Family-An Imitator of Rhus Dermatitis

The Euphorbiaceae family (commonly known as "spurge") is a large, diverse, and widely distributed family of plants that encompass around 300 genera and more than 8000 species. Their attractiveness and hearty nature have made them popular for both indoor ornamentation and outdoor landscaping. Despite their ubiquity, the potential to cause irritant contact dermatitis (ICD) is often overlooked in favor of more notorious causes of phytodermatitis, namely, Toxicodendron species and nettles. We examined case reports spanning 40 years and discovered that spurge-induced ICD tends to befall children and middle-aged adults who unwittingly encounter the plant through play or horticulture, respectively. Clinical presentation is pleomorphic. Erythema, edema, burning, vesicles, and pruritus of acute onset and rapid resolution are frequently observed. We present a classic case of ICD in a 12-year-old girl after exposure to Euphorbia myrsinites and review the literature on phytodermatitis caused by members of the Euphorbiaceae family.

Changes in dermal matrix in the absence of Rac1 in keratinocytes

Keratinocytes, in response to irritants, secrete pro-inflammatory mediators which recruit and activate immune and mesenchymal cells, including fibroblasts, to repair the skin. Fibroblasts respond by synthesising collagen and promoting the crosslinking extracellular matrix (ECM). We recently showed that the deletion of Rac1 in keratinocytes causes heightened inflammation due to aberrant crosstalk with immune cells. Indeed, the skin of these mice shows a higher inflammatory response to the induction of irritant contact dermatitis (ICD), and also even to treatment with a vehicle alone, compared with controls. As inflammation is intimately linked with fibrotic disease in the skin, this raised the question as to whether this deletion may also affect the deposition and arrangement of the dermal ECM. This study assessed the effects of Rac1 deletion in keratinocytes and of the heightened inflammatory status by induction of ICD on the tissue localisation and arrangements of dermal collagen. Qualitative analysis did not reveal evidence for the formation of pathologies in the dermis. However, quantitative analysis did reveal some perturbations in the dermal matrix, namely that only the combination of the lack of Rac1 and ICD affects the architectural organisation of the dermal collagen, and that a higher inflammatory state in the tissue (i.e. when Rac1 is deleted in the keratinocytes or ICD is induced in the skin, or a combination of both) influences the diameter of the collagen fibrils. It is proposed that this increase in the diameter of collagen fibrils due to inflammation may serve as pre-fibrotic marker enabling earlier determination of fibrosis and earlier treatment. This study has revealed previously unknown effects on the ECM due to the deletion of Rac1 in keratinocytes.

Prevalence of and Risk Factors for Skin Diseases Among Army Personnel and Flood Victims During the 2011 Floods in Thailand

OBJECTIVE

This study aimed to determine the prevalence of and risk factors for skin problems among flood victims and army personnel during the 2011 floods in Thailand.

METHODS

To determine the prevalence of and risk factors for skin symptoms, standardized questionnaires were used to collect demographic data, current skin symptoms, history of water exposure, and sanitary behaviors. A certified dermatologist evaluated those who presented with skin problems and provided diagnoses. Univariate and multivariate analyses were performed to assess independent risk factors for skin symptoms.

RESULTS

The most prevalent skin disease was irritant contact dermatitis. Flood victims showed a higher prevalence of skin symptoms compared with army personnel. Development of skin symptoms after exposure to floodwater was also observed earlier among flood victims. Having a history of skin diseases and delayed skin cleaning after exposure were also significant risk factors for the development of skin symptoms.

CONCLUSION

This information might be used as guidelines for protecting military personnel and to educate the general public regarding flood disaster management. (Disaster Med Public Health Preparedness. 2016;10:570-575).

Wet-work Exposure: A Main Risk Factor for Occupational Hand Dermatitis

Wet-work can be defined as activities where workers have to immerse their hands in liquids for >2 hours per shift, or wear waterproof (occlusive) gloves for a corresponding amount of time, or wash their hands >20 times per shift. This review considers the recent literature on wet-work exposure, and examines wet-work as a main risk factor for developing irritant contact dermatitis of the hands. The aim of this paper is to provide a detailed description of wet-work exposure among specific occupational groups who extensively deal with water and other liquids in their occupations. Furthermore, it highlights the extent and importance of the subsequent adverse health effects caused by exposure to wet-work.

Induction of a hardening phenomenon and quantitative changes of ceramides in stratum corneum

Background

Hardening phenomenon of human skin after repeated exposure to the irritants is well-known, but the precise mechanism remains elusive.

Objective

To modify the previous experimental model of hardening phenomenon by repeated applications of two different concentrations of sodium lauryl sulfate (SLS) solutions to Korean healthy volunteers and to investigate the quantitative changes of ceramides in stratum corneum before and after chronic repeated irritation.

Methods

Eight hundred microliters of distilled water containing 0.1% and 2% SLS was applied for 10 minutes on the forearm of 41 healthy volunteers for 3 weeks. After an intervening 3-week rest, 24-hour patch tests with 1% SLS were conducted on previously irritated sites. Transepidermal water loss (TEWL), erythema index and quantity of ceramide were measured in the stratum corneum before and after irritation.

Results

TEWL values on the sites preirritated with 2% SLS were lower than those with 0.1% SLS. Hardening phenomenon occurred in 24 volunteers at day 44. The changes in ceramide levels were not significantly higher in the hardened skin than in the non-hardened skin.

Conclusion

Repetitive stimulation with a higher concentration of SLS can more easily trigger skin hardening.

Metal concentrations in cosmetics commonly used in Nigeria

Trace amounts of potentially toxic metals can be either intentionally added to cosmetics or present as impurities in the raw materials. In the present study, the levels of lead, cadmium, nickel, chromium, and mercury have been assessed in 28 body creams and lotions, 10 powders, 3 soaps, 5 eye make-ups, and 4 lipsticks widely available on Nigerian markets. The increases over suggested or mandated levels of lead in these creams and lotions ranged from 6.1 to 45.9 and from 1.2 to 9.2 mg kg⁻¹ when compared with Cosmetic Ingredients Review Expert Panel 2007 and German safe maximum permissible limit of lead in cosmetics, respectively. About 61% of the body cosmetics, the lotions, and the creams contained detectable levels of nickel ranging from 1.1 to 6.4-9.2 mg kg⁻¹. Chromium and mercury were undetected in 100% of the cosmetic product. Taken together, lead and cadmium were high in creams and lotions. Most of the imported creams and creamy white coloured cosmetics contained higher levels of metal contaminants than the other colours. Regulatory Agencies in developing nations should take appropriate action for cosmetics that contain lead and cadmium beyond the reference limits.

Cytokines and chemokines in irritant contact dermatitis

Irritant contact dermatitis is a result of activated innate immune response to various external stimuli and consists of complex interplay which involves skin barrier disruption, cellular changes, and release of proinflammatory mediators. In this review, we will focus on key cytokines and chemokines involved in the pathogenesis of irritant contact dermatitis and also contrast the differences between allergic contact dermatitis and irritant contact dermatitis.