Oral fusidic acid for the treatment of mild-to-moderate hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a debilitating inflammatory skin disease. Tetracyclines are one of the few therapeutic options recommended for mild-to-moderate disease. This study aimed to investigate the efficacy of systemic fusidic acid's (FA) effectiveness in treating HS.

This retrospective study analyzed 55 FA therapy cycles (TC, average weekly dose: 6409 mg; range: 5250-9800 mg; 2-12 weeks) in 49 patients. The outcome was evaluated using the Physician's Global Assessment (PGA) scale. Therapy response was defined as any reduction of inflammatory activity without the occurrence of flares. We also characterized adverse events and investigated predictors for treatment success. Results were compared to a matched control group receiving doxycycline.

FA treatment (55 treatment cycles (TC); male: 45.5%; female: 54.5%) showed an overall response rate of 70.9% (39 TC). No worsening was observed. Significantly higher response rates were observed in females (83.3%, P = 0.026) and Hurley I (90.9%, P = 0.008). After multivariate adjustment, higher response rates were associated with the Hurley grade (P = 0.046) but not with gender (P = 0.0174). Adverse reactions (21.8% gastrointestinal symptoms) occurred in 27.3% (15 TC) and 46.7% within the first 4 weeks. Similar results were observed in the doxycycline control group (overall response rate: 76.4%).

Oral FA is safe and improves symptoms in most patients. HS patients could benefit from oral FA treatment, especially in case of contraindications or resistance to tetracyclines.