Adapalene is a synthetic naphthoic acid derivative, light stable, third generation retinoid with slightly better efficacy, lower incidence of side effects, and better tolerability profile in comparison with other topical retinoids that places it clinically above the rest in the treatment of acne vulgaris. Like other topical retinoids, adapalene reverses the abnormal follicular desquamation and also have anti-inflammatory effects.1-4 A strong anti-comedonal effect of topical retinoids has been shown in animal experiments. Clinical trials have also revealed that they act efficaciously against microcomedo, the natural precursor of comedones.5,6
Benzoyl peroxide (BPO) is another safe and effective topical agent for treating acne vulgaris. This medication has both anticomedogenic and antimicrobial properties, with no fear of antibiotic resistance.7,8 Its primary limitations are concentration-dependent cutaneous irritation and dryness in certain patients, which are amenable to be prevented thorough using lower but still effective doses.9
It is previously claimed that the efficacy of adapalene on noninflammatory and inflammatory lesions is comparable to the efficacy of BPO in cases with mild to moderate acne vulgaris.10-15
Based on the most recent guidelines, topical retinoids and BPO could be used alone or in combinations with anti-microbial agents in mild to moderate, inflammatory or non-inflammatory acne vulgaris.16
However, no high strength recommendation has been given in the cases with mild acne vulgaris because of the general lack of direct evidence for the treatment of this type of the disease.17
Furthermore, initial use of topical BPO than topical retinoids has been advocated on the grounds of cost and on a longer track record of efficacy and safety by some researches.18
The present clinical trial aims to compare the efficacy and safety profile of topical adapalene 0.1% and BPO 2.5% gels in patients with mild acne vulgaris.
In this single-center, randomized, double-blind, parallel, clinical trial, 60 patients with mild acne vulgaris (Evaluator Global Severity Score, EGSS, of 2) were recruited from a teaching clinic of dermatology from January 2011 through April 2012.
Patients with severe acne or other dermatologic conditions requiring systemic therapy, as well as nursing/pregnant women, and those who were planning for pregnancy were not included.
A â€˜washoutâ€™ period of at least 2 weeks of topical antibiotics and corticosteroid, 1 month of oral antibiotics and corticosteroid, and 6 months of oral retinoid agent prior to the start of treatment was required. No other treatment was allowed during the study period.