Background: Antibiotic resistance is a major concern, especially in HS. However, antibiotics form a cornerstone in its treatment. Topical clindamycin is known to cause bacterial resistance, but is still advised as monotherapy for the treatment of mild to moderate HS Methods This is a randomized controlled, assessor blinded, intra-patient pilot trial to compare the clinical efficacy of clindamycin-benzoyl peroxide gel with clindamycin lotion in patients with mild to moderate HS. Two contralateral body sites were randomized for treatment in each patient. The primary outcome was the difference in the International Hidradenitis Suppurativa Severity Score (IHS4) between the two groups after 12 weeks. Secondary objectives were: feasibility of the intra-patient design, efficacy within treatment groups, effect on HS pain, HS itch, patient satisfaction, antibiotic resistance, and the prolonged efficacy after 16 weeks. Results Ten patients were included resulting in two groups of 10 treated body sites. No significant differences were found between the two groups for all measurements after 12 or 16 weeks while both therapies lead to an improvement in the IHS4, pain and itch scores. A significant decrease was observed in the IHS4 for both the clindamycin lotion (-1,5; p

The Author(s). Published by S. Karger AG, Basel