A comparison of the clinical efficacy of topical acne lotion and 2.5%benzoyl peroxide versus topical acne lotion and 2%erythromycin solution in the treatment of mild to moderate back acne

Abstract

Background: Acne vulgaris is a common skin disorder. The prevalence of acne with truncal involvement is 50-61% of all acne patients. The inflammatory lesions of truncal acne usually heal with atrophic scar or keloid. Acne lotion (Institute of Dermatology,Thailand formulary) was commonly used to treat truncal acne for many years, but there has no  trial done to prove its effectiveness. However, the combined therapies with either 2.5%benzoyl peroxide versus 2% erythromycin solution which have different mechanisms may have synergistic interactions.

Objectives : To evaluate efficacy of topical acne lotion (AL) and 2.5% benzoyl peroxide (BP) versus topical acne lotion (AL) and 2% erythromycin solution (ES) in mild to moderate back acne.

Meterials and Methods : Total of sixty-three patients from Dermatology Out-patients Clinic, Institute of Dermatology Bangkok, Thailand during 1 January 2013 to 31 October 2013 with mild to moderate  acne of the back who aged older than 18 years were enrolled. Pityrosporum folliculitis was excluded. Baseline characteristic, clinical presentations and associated factors were recorded. Comedone extraction to evaluate prevalence of Propionibacterium acnes was done in all patients. Each patient was randomized to receive either treatment with AL and BP or AL and ES applying twice daily for 12 weeks. Acne lesion counts were assessed at baseline and at the 4^th , 8^th, and 12^th week. Side effect of the treatment and patient’s satisfaction  were also assessed.

Results : Both combinations showed the efficacy in reducing total number of lesions, inflammatory lesions and non-inflammatory lesions in mild to moderate back acne, but no  significant difference was seen between the two groups (p>0.05). The AL plus ES group showed decrease number of pustular lesions more than the other group, but there was no significant difference (p>0.05). Report of at least one side effect was found in 59.4% in the AL plus BP group and 61.3% in the AL plus ES group, most side effects were mild to moderate in severity.  One patient from each group have to withdraw from the trial due to side effects. No significant statistical difference found between the two groups as to side effect analysis (p>0.05). Patient satisfaction in efficacy, side effects and the convenience of drug application did not show significant difference (p>0.05).

Conclusions : Both of AL plus BP and AL plus ES regimens were effective in back acne treatment, they can decrease number of lesion counts from baseline. Both combinations did not show difference in efficacy and side effects in mild to moderate back acne .