Filaggrin expression and the pathogenesis of epidermal cysts

Rare Cutaneous Side Effects of Imiquimod: A Review on Its Mechanisms, Diagnosis, and Management

As an immune-response modifier, imiquimod can bind to Toll-like receptors on immune cells and enhance innate and adaptive immune responses, exerting potential antitumor and antiviral effects, which led to its approval by the US Food and Drug Administration for the treatment of actinic keratosis, superficial basal cell carcinomas, and anogenital warts, and to its off-label use in treating many other benign and malignant dermatoses. Although topical administration of imiquimod has been considered well tolerated, an increasing number of cutaneous and noncutaneous side effects are being reported as its clinical applications expand. This review primarily focuses on rare cutaneous side effects. To the best of our knowledge, this is the first article to summarize the mechanism, diagnosis, and management of rare cutaneous side effects of imiquimod, which may help to heighten awareness among physicians, especially dermatologists, about potential imiquimod-induced cutaneous side effects.

Investigation of fungus at stratum corneum of patients with acne vulgaris

BACKGROUND

The pathophysiology of acne is complex and multifactorial. In recent years, fungal infections have increased significantly.

OBJECTIVES

The purpose of this study was to evaluate the role of fungi in the etiopathogenesis of acne vulgaris.

METHODS

This was a prospective case-control study. A total of 200 individuals (100 with acne vulgaris and 100 without acne vulgaris) were enrolled in the study. Direct microscopic investigation and culturing of the samples were done according to Clinical and Laboratory Standards Institute criteria. Descriptive analyses, independent sample t-tests, and chi-squared tests were used for statistical analysis. The subjects in the control group were paired by age and gender with the patients.

RESULTS

Direct microscopic examination revealed hyphae in the samples of all subjects with acne and in the samples of four of the healthy controls. The cultures of 18 of the patients with acne vulgaris were positive for the following: 6 with Aspergillus spp., 7 with Penicillium spp., 3 with Cladosporium spp., 1 with Candida spp., and 1 with Acremonium spp. In addition, Candida spp. was observed in the cultures of two of the healthy controls.

CONCLUSION

We conclude that fungi may be involved in the etiopathogenesis of acne vulgaris.

Recent advances in understanding and managing acne

Multidisciplinary investigations into the pathogenesis of acne have significantly progressed over the past three years. Studies of the etiology of acne from the perspectives, for example, of sebaceous gland biology, sebum, genetics, keratinization, differentiation, hair cycles, immunology, bacteriology, and wound healing have elucidated its pathogenesis. This has led to the development of new therapies and paved the way for advanced studies that will enable the further evolution of acne treatment.

Profile of clindamycin phosphate 1.2%/benzoyl peroxide 3.75% aqueous gel for the treatment of acne vulgaris

Acne vulgaris is a common and chronic skin disease, and is a frequent source of morbidity for affected patients. Treatment of acne vulgaris is often difficult due to the multifactorial nature of this disease. Combination therapy, such as that containing clindamycin and benzoyl peroxide, has become the standard of care. Several fixed formulations of clindamycin 1% and benzoyl peroxide of varying concentrations are available and have been used with considerable success. The major limitation is irritation and dryness from higher concentrations of benzoyl peroxide, and a combination providing optimal efficacy and tolerability has yet to be determined. Recently, a clindamycin and benzoyl peroxide 3.75% fixed combination formulation was developed. Studies have suggested that this formulation may be a safe and effective treatment regimen for patients with acne vulgaris. Here, we provide a brief review of acne pathogenesis, benzoyl peroxide and clindamycin, and profile a new Clindamycin-BP 3.75% fixed combination gel for the treatment of moderate-to-severe acne vulgaris.

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.

Atopic eczema and the filaggrin story

The discovery that null mutations in the filaggrin gene (FLG) are associated with atopic eczema represents the single most significant breakthrough in understanding the genetic basis of this complex disorder. The association has been replicated in multiple independent studies during the past 2 years with the use of various methodologies, from populations in Europe, the United States, and Japan. Filaggrin plays a key role in epidermal barrier function, and its association with atopic eczema emphasizes the importance of barrier dysfunction in eczema pathogenesis. This review aims to summarize the current state of knowledge regarding the role of FLG mutations in ichthyosis vulgaris, atopic eczema, and other skin disorders, with an emphasis on potential clinical applications. Further research is needed to clarify the precise role of filaggrin in skin and systemic atopic disease, to pave the way for novel therapeutic interventions.