INTRODUCTION
Acne is a very common disease that remains prevalent
in adults, with more adult women being afflicted than
adult men.1 This raises the intriguing possibility that
gender differences in skin may influence acne pathogenesis and
response to acne treatment. Indeed, gender differences in skin,
both its function and structure, have been the focus of considerable research to understand more about skin disease pathogenesis and response to treatment. For example, gender differences
in skin surface pH have been reported, although findings have
been inconsistent.2-7 It has also been shown that males have
thicker skin than females,8 while females have thicker subcutaneous tissues than males.9 Skin thickness tends to decrease with
age, especially in women, suggesting that estrogens play a role
in maintaining skin.10 Estrogens also have been implicated in
regulating the composition of stratum corneum sphingolipids11
and cutaneous protein5 and in decreasing sebum production.12,13
In contrast, androgens appear to increase sebum production,14
possibly by influencing cell proliferation and lipogenesis in the
sebaceous gland.14 Sebum production and sebaceous gland activity are major factors in acne lesion development.
Dapsone is an anti-inflammatory agent that, in the 5% gel formulation, is an effective topical treatment for patients with acne vulgaris.15 It has been studied and found to be effective for at
least 12 months of treatment16 and to reduce comedonal as well
as papulopustular acne lesions when used as monotherapy15 or
in combination with a retinoid.17,18 During clinical trials of dapsone 5% gel, some investigators observed a greater acceptance
and efficacy of the product in female patients vs in male patients. Given this observation, and previously reported gender
differences in skin and acne,19 we explored whether gender impacts the efficacy and tolerability of dapsone 5% gel.
METHODS
Patients, Treatment, and Assessments
The two 12-week, double-blind trials (DAP0203 and DAP0204) enrolled patients 12 years and older with facial acne vulgaris. Patients
had 20 to 50 papulopustular lesions and 20 to 100 comedones
above the mandibular line at baseline. Other exclusion criteria
and study design details are reported in the original study publication.15 Patients were randomized 1:1 to receive either dapsone 5%
gel or vehicle gel. Assessments were performed at baseline and at
weeks 2, 4, 6, 8, and 12. The following parameters were analyzed
and compared in female vs male patients at all time points: the
mean percentage reduction from baseline in acne lesion counts
(papulopustular, comedonal, and total); the proportion of patients