Gender as a Clinically Relevant Outcome Variable in Acne: Benefits of a FixedCombination Clindamycin Phosphate (1.2%) and Benzoyl Peroxide (2.5%)Aqueous Gel

December 2012 | Volume 11 | Issue 12 | Original Article | 1440 | Copyright © December 2012

Julie C. Harper MD

The Dermatology and Skin Care Center of Birmingham, Birmingham, AL

Abstract
Objective: There is an increasing interest in gender differences both in the pathogenesis and treatment of skin diseases. We investigate whether there were any treatment differences in male and female subjects treated with clindamycin phosphate 1.2%/benzoyl peroxide (BPO) 2.5% gel as monotherapy for moderate to severe acne.
Methods: We performed a post hoc analysis of the efficacy and cutaneous tolerability in 797 subjects receiving clindamycin phosphate 1.2%/BPO 2.5% gel from two 12-week, multicenter studies that enrolled 2,813 subjects with moderate to severe acne. Efficacy and tolerability were compared with both male and female subjects, overall and stratified by age (12-18 years and ≥18 years).
Results: Absolute mean reductions in lesion counts with clindamycin phosphate 1.2%/BPO 2.5% gel were comparable and not significantly different across gender and age groups. Net reductions were greater in the adolescent groups. Treatment success in the older males was significantly greater (P=.046) compared with the adolescent males, and the difference between the male and female adolescent groups was significant in favor of the female subjects (P=.046). Cutaneous tolerability was comparable across all groups and between clindamycin phosphate 1.2%/BPO 2.5% gel and vehicle.
Conclusions: Clindamycin phosphate 1.2%/BPO 2.5% gel provided comparable reductions in lesion counts across all 4 groups; however, the impact was greater in those subjects with more severe acne (the older males and adolescent females), and net benefit was greater in the adolescent subjects.

J Drugs Dermatol. 2012;11(12):1440-1445.

INTRODUCTION

There has been increasing interest in studying gender differences in skin disease to learn more about pathogenesis and to discover more effective treatments.1 The mechanisms underlying any gender differences in a variety of skin diseases remain largely unknown. Differences in the skin's structure and physiology, the effect of sex hormones, ethnic background, sociocultural behavior, and environmental factors may all have a part to play.2
It is well recognized that a number of key factors contribute to the pathogenesis of acne, including follicular epidermal hyperproliferation and follicle plugging, an excess of sebum, the presence and activity of Propionibacterium acnes, and inflammation.3 A clear physiological link has been established between steroid hormones and acne in both males and females. Androgen hormones bind and activate the androgen receptor in the sebaceous gland and in the follicular epithelium. Some conditions with an associated hyperandrogenism, such as polycystic ovarian syndrome or an androgen-secreting tumor, present with acne. However, most men and women with acne have normal circulating levels of steroid hormones.4 Adult males have higher androgen hormones levels in the adult years than do females, but acne is more common in the female population in this age group.
Gender differences have largely been ignored when reviewing clinical data and outcomes in acne, yet unlike other diseases, there is often a more equivalent distribution of subjects by sex with acne, and in some cases, a greater proportion of females included in these studies. Female acne patients have been shown to report worse quality of life than male acne patients.5 In terms of acne presentation, it is generally accepted that nodulocystic acne is more prevalent in adolescent male patients.6 Acne on the lower face and jawline and cyclical flaring of lesions may be associated with hormonally mediated acne in females.7
A recent study of dapsone 5% gel suggested that efficacy results appear to be influenced by gender, with female subjects experiencing a significantly greater reduction in acne lesion counts than their male counterparts following 12 weeks of therapy. There was no gender difference in the incidence of adverse events (AEs) reported by treated subjects.8
As well as gender, there are differences relating to the patient's age. Comedones are prominent in adolescent acne, and the acne frequently presents in the T-zone and on the trunk. Adult female acne is oftentimes nodular, and comedones are not clinically prominent. Adult females present with acne on the lower face and jawline in the U-zone.9