Identification of histamine receptors and reduction of squalene levels by an antihistamine in sebocytes

Oral isotretinoin with desloratadine compared with oral isotretinoin alone in the treatment of moderate to severe acne: a randomized, assessor-blinded study

BACKGROUND

Our aim was to measure the effectiveness of oral isotretinoin with desloratadine compared with oral isotretinoin alone in treating moderate to severe acne at a tertiary care teaching hospital in North India. In this study, 90 patients with moderate to severe acne were enrolled to participate based on their fulfilling the inclusion criteria.

METHODS

A randomized, assessor-blinded, parallel-arm study was conducted. Randomization was done using computer-generated tables to allocate treatments in a 1:1 ratio. A low-dose oral isotretinoin at a dose of 0.3 mg/kg/day with tab desloratadine at 5 mg/day was applied to the study group and compared against the same patients going without the dosage when controls were conducted. Follow-up was at 4, 8, and 12 weeks.

RESULTS

The primary outcome was an improved global acne grading system (GAGS) score and decreased acne lesion count.

SECONDARY OUTCOME

patient satisfaction with treatment. The 90 participants were randomized and 15 participants dropped out of the study, leaving 75 participants for intention to treat analysis (n = 41, n = 30). At week 12, the GAGS score and acne lesion count between the study and control groups were comparable (P > 0.05). Pruritus reported was 9.76% in the study versus 33.33% in the control group (P = 0.018). Also, 53.66% of participants reported "excellent" treatment satisfaction in the study group versus 36.67% in the control group.

CONCLUSIONS

The addition of desloratadine to an isotretinoin regimen has a role in reducing disease and therapy-related pruritus in acne and leads to improved patient satisfaction.

Use of Oral Supplements and Topical Adjuvants for Isotretinoin-Associated Side Effects: A Narrative Review

Acne is a chronic inflammatory disease of the pilosebaceous unit with a multifactorial etiology and is one of the most common conditions treated by dermatologists and primary care physicians. Within an extensive and evolving treatment landscape, oral isotretinoin has demonstrated efficacy for treatment of severe, recalcitrant acne. Several side effects of isotretinoin have been reported, including laboratory abnormalities, mucocutaneous, and musculoskeletal effects, which may reduce compliance and patient satisfaction with treatment. In this narrative review, we aim to review the efficacy and safety profile of oral supplements or topical adjuvant therapies in mitigating isotretinoin-associated mucocutaneous and musculoskeletal side effects. Oral supplements reviewed include omega-3 fatty acids, vitamin E, folic acid and vitamin B12, antihistamines, l-carnitine, biotin, and combined oral supplements. Topical adjuvants include a hyaluronic acid, biosaccharide gum-2, and glycerine gel-cream; a nongreasy, noncomedogenic, fragrance-free moisturizing cream; dexpanthenol; trichloroacetic acid; and a combination cream. Most of the supplements and topical adjuvants demonstrated efficacy with an adequate level of supporting evidence and no reported adverse events, indicating an adequate safety profile. Patients on isotretinoin may benefit from using oral supplements and topical adjuvants to minimize primarily mucocutaneous side effects, increase adherence to treatment, and thereby improve overall outcomes.

Insulin and the sebaceous gland function

Insulin affects metabolic processes in different organs, including the skin. The sebaceous gland (SG) is an important appendage in the skin, which responds to insulin-mediated signals, either directly or through the insulin growth factor 1 (IGF-1) axis. Insulin cues are differently translated into the activation of metabolic processes depending on several factors, including glucose levels, receptor sensitivity, and sebocyte differentiation. The effects of diet on both the physiological function and pathological conditions of the SG have been linked to pathways activated by insulin and IGF-1. Experimental evidence and theoretical speculations support the association of insulin resistance with acne vulgaris, which is a major disorder of the SG. In this review, we examined the effects of insulin on the SG function and their implications in the pathogenesis of acne.

A New Topical Candidate in Acne Treatment: Characterization of the Meclozine Hydrochloride as an Anti-Inflammatory Compound from In Vitro to a Preliminary Clinical Study

Acne is a chronic inflammatory multifactorial disease involving the anaerobic bacterium Cutibacterium acnes (C. acnes). Current acne treatments are associated with adverse effects, limiting treatment compliance and use. We showed that meclozine, an anti-histaminic H1 compound, has anti-inflammatory properties. In Vitro, meclozine reduced the production of CXCL8/IL-8 and IL-1β mRNA and protein by C. acnes-stimulated human keratinocytes and monocytes. No cell toxicity was observed at the IC50. Meclozine prevented the phosphorylation of ERK and JNK. In Vivo, 1% meclozine gel significantly decreased C. acnes-mouse ear induced inflammation by 26.7% (p = 0.021). Ex vivo experiments on human skin explants showed that meclozine decreased the production of GM-CSF, IL-1β and TNF-α at transcriptional and translational levels. In a randomized, double-blind, placebo-controlled proof-of-concept clinical trial on 60 volunteers, 2% meclozine pharmaceutical gel decreased by 20.1% (p < 0.001) the ASI score in the treated group after 12 weeks of treatment. No adverse event was reported. Together, these results indicate that meclozine is a potent topical anti-inflammatory compound of potential value for acne treatment.

Prevalence and Cutaneous Comorbidity of Acne Vulgaris in the Working Population

Purpose

Although acne vulgaris (AV) is a common disease and can persist into adulthood, there are few large-scale epidemiological studies on the prevalence of acne vulgaris in adults. The aim of our study was to characterise the epidemiology and comorbidity of acne vulgaris in working adults in Germany.

Patients and Methods

Within the framework of a cross-sectional study, a total of 161,269 employees underwent dermatological whole-body examinations in more than 500 German companies between 2001 and 2016. Point prevalence rates for acne vulgaris and further skin diseases and their 95% confidence intervals were calculated and differences between participants with and without acne vulgaris were tested with chi-squared tests.

Results

Mean age was 43.2 years ± 10.9, 55.5% were male. In total, n = 5311 people (3.3%) with acne vulgaris were identified. Prevalence decreased by age. Controlling for age and gender, acne was significantly associated with folliculitis (OR = 1.91; CI: 1.76–2.07), contact dermatitis (OR = 1.74; CI: 1.08–2.81), rosacea (OR = 1.74; CI: 1.40–2.15), pyoderma (OR = 1.58; 1.22–2.06), seborrheic dermatitis (OR = 1.47; CI: 1.27–1.71), hand eczema (OR = 1.34; CI: 1.00–1.76), verruca vulgaris plantaris (OR = 1.29; CI: 1.09–1.51), tinea pedis (OR = 1.27; CI: 1.10–1.47), spider veins (OR = 1.26; CI: 1.16–1.38) and telangiectasia (OR = 1.15; CI: 1.02–1.30).

Conclusion

These data underline the importance of acne vulgaris in the adult population. Further studies to better understand the pathophysiology of AV and its comorbidity in different phases of adulthood would be desirable to develop appropriate guidelines and therapy concepts.

Lipid Cubic Systems for Sustained and Controlled Delivery of Antihistamine Drugs

Antihistamines are capable of blocking mediator responses in allergic reactions including allergic rhinitis and dermatological reactions. By incorporating various H1 receptor antagonists into a lipid cubic phase network, these active ingredients can be delivered locally over an extended period of time owing to the mucoadhesive nature of the system. Local delivery can avoid inducing unwanted side effects, often observed after systematic delivery. Lipid-based antihistamine delivery systems are shown here to exhibit prolonged release capabilities. In vitro drug dissolution studies investigated the extent and release rate of two model first-generation and two model second-generation H1 antagonist antihistamine drugs from two monoacyglycerol-derived lipid models. To optimize the formulation approach, the systems were characterized macroscopically and microscopically by small-angle X-ray scattering and polarized light to ascertain the mesophase accessed upon an incorporation of antihistamines of varying solubilities and size. The impact of encapsulating the antihistamine molecules on the degree of mucoadhesivity of the lipid cubic systems was investigated using multiparametric surface plasmon resonance. With the ultimate goal of developing therapies for the treatment of allergic reactions, the ability of the formulations to inhibit mediator release utilizing RBL-2H3 mast cells with the propensity to release histamine upon induction was explored, demonstrating no interference from the lipid excipient on the effectiveness of the antihistamine molecules.

Use of H-1 Antihistamine in Dermatology: More than Itch and Urticaria Control: A Systematic Review

H-1 antihistamines are commonly used in dermatological practice for itch and urticaria control. The widespread expression of H-1 receptor on different cells in the skin and various biologic functions of H-1 antihistamines indicate the possible treatment potentials of H-1 antihistamines in dermatology. A literature search was performed on PubMed and Embase, targeting articles reporting use of antihistamine for purposes other than itch and urticaria control in dermatological practice. Several off-label usages of antihistamines were identified, including alopecia, acne, Darier disease, eosinophilic dermatoses, paraneoplastic dermatoses, psoriasis, lichen nitidus, radiation dermatitis, skin dysesthesia, and cutaneous malignancies. Additional benefits were observed when H-1 antihistamines were used either alone or in combination with other therapeutic modalities. Although various novel uses of H-1 antihistamines have been uncovered, the evidence level of most included studies is weak. Further randomized control trials are warranted to better evaluate the efficacy and dosage of H-1 antihistamine for dermatological disorders.

A strategic review on the involvement of receptors, transcription factors and hormones in acne pathogenesis

Acne vulgaris is a very common pilosebaceous inflammatory disease occurring primarily on the face and also rare on the upper arms, trunk, and back, which is caused by Propionibacterium, Staphylococcus, Corynebacterium, and other species. Pathophysiology of acne comprises of irregular keratinocyte proliferation, differentiation, increased sebum output, bacterial antigens and cytokines induced inflammatory response. Treatment of acne requires proper knowledge on the pathophysiology then only the clinician can come out with a proper therapeutic dosage regimen. Understanding the pathophysiology not only includes the mechanism but also involvement of receptors. Thus, this review is framed in such a way that the authors have focused on the disease acne vulgaris, pathophysiology, transcription factors viz. the Forkhead Box O1 (FoxO1) Transcription Factor, hormones like androgens and receptors such as Histamine receptors, Retinoic receptor, Fibroblast growth factor receptors, Toll like receptor, Androgen receptor, Liver X-receptor, Melanocortin receptor, Peroxisome proliferator-activated receptor and epidermal growth factor receptors involvement in the progression of acne vulgaris.

Beyond acne: Current aspects of sebaceous gland biology and function

The sebaceous gland is most commonly found in association with a hair follicle. Its traditional function is the holocrine production of sebum, a complex mixture of lipids, cell debris, and other rather poorly characterized substances. Due to the gland's central role in acne pathogenesis, early research had focused on its lipogenic activity. Less studied aspects of the sebaceous gland, such as stem cell biology, the regulation of cellular differentiation by transcription factors, the significance of specific lipid fractions, the endocrine and specially the neuroendocrine role of the sebaceous gland, and its contribution to the innate immunity, the detoxification of the skin, and skin aging have only recently attracted the attention of researchers from different disciplines. Here, we summarize recent multidisciplinary progress in sebaceous gland research and discuss how sebaceous gland research may stimulate the development of novel therapeutic strategies targeting specific molecular pathways of the pathogenesis of skin diseases.

Top Ten List of Clinical Pearls in the Treatment of Acne Vulgaris

Acne represents the most common inflammatory dermatosis seen worldwide and is the leading reason for seeing a dermatologist. This article provides some tips for managing acne in a safe and effective manner to minimize the physical and psychological scars that can result from acne. Tips include how to optimize available treatment regimens according to the evidence base and target therapy to pathophysiologic factors, while also tailoring treatments to patient expectation and needs. Attention is given to minimizing the emergence of antimicrobial resistance in acne patients and beyond.

Effect of antihistamine as an adjuvant treatment of isotretinoin in acne: a randomized, controlled comparative study

BACKGROUND

Isotretinoin has been frequently used for acne therapy. However, it has limitation in acceptance because of its adverse effects. Although antihistamine recently revealed to decrease the lipogenesis, evidence is lacking regarding the clinical relevance of antihistamine in the treatment of acne.

OBJECTIVES

To evaluate the clinical efficacy and tolerability of antihistamine as an adjuvant treatment of isotretinoin.

METHODS

Forty patients with moderate acne were included in this randomized, controlled comparative study. Twenty patients were treated with isotretinoin and 20 patients were treated with additional antihistamine, desloratadine. Assessment was made at baseline, after 2, 4, 8 and 12 weeks of treatment.

RESULTS

At week 12, compared with isotretinoin only group, isotretinoin with additional antihistamine group showed more statistically significant decrease in acne lesion counts (non-inflammatory lesions: 44.8% vs. 17.8%; inflammatory lesions: 55.8% vs. 22.9%; total lesions: 45.6% vs. 18.7%; all P < 0.05). Significant decrease was also observed in the score of global acne grading system and the measured value of sebum and erythema. Moreover, acne flare during the treatment occurred less frequently and adverse events of isotretinoin were more tolerable in additional antihistamine group.

CONCLUSIONS

This results provide early evidence that antihistamine has a synergic effect with minimizing the side-effect of isotretinoin, and may be used as an adjuvant treatment of moderate acne.

Hormones and the pilosebaceous unit

Hormones can exert their actions through endocrine, paracrine, juxtacrine, autocrine and intracrine pathways. The skin, especially the pilosebaceous unit, can be regarded as an endocrine organ meanwhile a target of hormones, because it synthesizes miscellaneous hormones and expresses diverse hormone receptors. Over the past decade, steroid hormones, phospholipid hormones, retinoids and nuclear receptor ligands as well as the so-called stress hormones have been demonstrated to play pivotal roles in controlling the development of pilosebaceous units, lipogenesis of sebaceous glands and hair cycling. Among them, androgen is most extensively studied and of highest clinical significance. Androgen-mediated dermatoses such as acne, androgenetic alopecia and seborrhea are among the most common skin disorders, with most patients exhibiting normal circulating androgen levels. The "cutaneous hyperandrogenism" is caused by in stiu overexpression of the androgenic enzymes and hyperresponsiveness of androgen receptors. Regulation of cutaneous steroidogenesis is analogous to that in gonads and adrenals. More work is needed to explain the regional difference within and between the androgn-mediated dermatoses. The pilosebaceous unit can act as an ideal model for studies in dermato-endocrinology.

Sebaceous gland receptors

Receptors are proteins, embedded in a cell or cytoplasmic membrane, to which a mobile signaling molecule may attach. Receptor ligands may be peptides (such as neurotransmitters), hormones, pharmaceutical drugs and/or a toxins, whereas "binding" ordinarily initiates a cellular response. Human sebocytes are biologically and metabolically very active cells and consequently express numerous receptors. Three of four groups of peptide/neurotransmitter receptors, the so-called serpentine receptor group are present (corticotropin-releasing hormone receptors 1 and 2, melanocortin-1 and 5 receptors, mu-opiate receptors, VPAC receptors, cannabinoid receptors 1 and 2, vascular endothelial growth factor receptor and histamine 1 receptor). The single-transmembrane domain receptors are represented by the insulin-like growth factor-I receptor and the third group, which does not possess intrinsic tyrosine kinase activity, by the growth factor receptor. Nuclear receptors expressed in sebocytes are grouped into two major subtypes. From the steroid receptor family, the androgen receptor and the progesterone receptor are expressed. The thyroid receptor family includes the estrogen receptors (alpha and beta isotypes), the retinoic acid receptors (isotypes alpha and gamma) and retinoid X receptors (isotypes alpha, beta, gamma), the vitamin D receptor, the peroxisome proliferator-activated receptors (isotypes alpha, delta and gamma) and the liver X receptors (alpha and beta isotypes). The vanilloid receptor belongs to the transient ion channels and is expressed in differentiating human sebocytes. Further sebocyte receptors, which may influence their function are fibroblast growth factor receptor 2, epidermal growth factor receptor, c-MET, CD14, Toll-like receptor 2, Toll-like receptor 4 and Toll-like receptor 6. Receptor-ligand interactions control sebocyte proliferation, differentiation and lipid synthesis. However, not every ligand that binds to a sebocyte receptor also activates it, such ligands are receptor antagonists and inverse agonists.

[The sebaceous gland]

The development and function of the sebaceous gland in the fetal and neonatal periods appear to be regulated by maternal androgens and by endogenous steroid synthesis, as well as by other morphogens. The most apparent function of the glands is to excrete sebum. A strong increase in sebum excretion occurs a few hours after birth; this peaks during the first week and slowly subsides thereafter. A new rise takes place at about age 9 years with adrenarche and continues up to age 17 years, when the adult level is reached. The sebaceous gland is a target organ but also an important formation site of hormones, and especially of active androgens. Hormonal activity is based on an hormone (ligand)-receptor interaction, whereas sebocytes express a wide spectrum of hormone receptors. Androgens are well known for their effects on sebum excretion, whereas terminal sebocyte differentiation is assisted by peroxisome proliferator-activated receptor ligands. Estrogens, glucocorticoids, and prolactin also influence sebaceous gland function. In addition, stress-sensing cutaneous signals lead to the production and release of corticotrophin-releasing hormone from dermal nerves and sebocytes with subsequent dose-dependent regulation of sebaceous nonpolar lipids. Among other lipid fractions, sebaceous glands have been shown to synthesize considerable amounts of free fatty acids without exogenous influence. Atopic dermatitis, seborrheic dermatitis, psoriasis and acne vulgaris are some of the disease on which pathogenesis and severity sebaceous lipids may or are surely involved.

New developments in our understanding of acne pathogenesis and treatment

Interest in sebaceous gland physiology and its diseases is rapidly increasing. We provide a summarized update of the current knowledge of the pathobiology of acne vulgaris and new treatment concepts that have emerged in the last 3 years (2005-2008). We have tried to answer questions arising from the exploration of sebaceous gland biology, hormonal factors, hyperkeratinization, role of bacteria, sebum, nutrition, cytokines and toll-like receptors (TLRs). Sebaceous glands play an important role as active participants in the innate immunity of the skin. They produce neuropeptides, excrete antimicrobial peptides and exhibit characteristics of stem cells. Androgens affect sebocytes and infundibular keratinocytes in a complex manner influencing cellular differentiation, proliferation, lipogenesis and comedogenesis. Retention hyperkeratosis in closed comedones and inflammatory papules is attributable to a disorder of terminal keratinocyte differentiation. Propionibacterium acnes, by acting on TLR-2, may stimulate the secretion of cytokines, such as interleukin (IL)-6 and IL-8 by follicular keratinocytes and IL-8 and -12 in macrophages, giving rise to inflammation. Certain P. acnes species may induce an immunological reaction by stimulating the production of sebocyte and keratinocyte antimicrobial peptides, which play an important role in the innate immunity of the follicle. Qualitative changes of sebum lipids induce alteration of keratinocyte differentiation and induce IL-1 secretion, contributing to the development of follicular hyperkeratosis. High glycemic load food and milk may induce increased tissue levels of 5alpha-dihydrotestosterone. These new aspects of acne pathogenesis lead to the considerations of possible customized therapeutic regimens. Current research is expected to lead to innovative treatments in the near future.