BACKGROUND
Acne vulgaris affects about 45 million people in the United States, and 85% of those aged 12 to 24 years.1-3 Acne
vulgaris causes significant physical and psychological
morbidity.1-3 Topical antibiotics, keratolytics, and retinoids are
the main first-line treatment options for comedonal and mild
inflammatory acne.4 Combination therapy is often used in
many clinical settings in order to target different pathogenic
factors.5,6 Retinoids in particular have shown superior clinical
efficacy when combined with another agent, eg, an antibiotic,
as this offers a multimodality approach to treating acne.7
Two major barriers to successful treatment with these agents is
the difficulty in adhering to continued daily or twice-daily use
and their irritant properties. Compliance decreases because of
both issues. Newer compound formulations of 2 medications
have been developed to address the former issue and indeed
to improve compliance.8,9 The tolerability of topical medications
has been addressed by improved vehicle preparations and micronization of agents, but the potential for irritancy still remains.
The first 2 topical acne preparations combining medications approved by the US Food and Drug Administration were released in 2006 and 2008. The first, a formulation of clindamycin 1.2%
and tretinoin 0.025% (CLIN/RA), has been shown to be significantly better tolerated than tretinoin 0.1% gel microspheres in
terms of redness, scaling, itching, burning, and stinging.10 In addition, there was a trend toward better tolerability of CLIN/RA
when compared with adapalene 0.1% gel (ADA) monotherapy.10
The second approved combination product of benzoyl peroxide
2.5% and ADA (BPO/ADA) was also found to have better tolerability than BPO monotherapy in terms of cutaneous tolerability.6 No
studies to date have compared these 2 products to each other.
The aim of the current study was to compare the tolerability of
CLIN/RA and BPO/ADA fixed-dose combination therapies using
objective and subjective measures of skin irritancy.
METHODS
Study Population
Twenty-four Caucasian subjects were enrolled in the study (27
subjects were screened, and 3 were excluded because they failed
to meet inclusion and exclusion criteria). Inclusion criteria were: 1)
diagnosis of mild to moderate facial acne vulgaris at baseline (20-150 total acne lesions, including 10-100 noninflammatory lesions
and/or 10-50 inflammatory lesions, and no more than 2 cysts/
