Effectiveness and Safety of 40 mg Modified-Release Doxycycline for the Treatment of Hidradenitis Suppurativa: A Single-Center Retrospective Observational Study

INTRODUCTION: Hidradenitis suppurativa (HS) is a chronic inflammatory follicular disorder commonly managed with antibiotics, despite increasing antimicrobial resistance (AMR). METHODS: This single-center retrospective study evaluated the efficacy and safety of 40 mg modified-release doxycycline (MR-DC) in 66 adults with HS treated for 28 days. RESULTS: Response to treatment was assessed using the Hidradenitis Suppurativa Clinical Response (HiSCR) and the International Hidradenitis Suppurativa Severity Score System (IHS4) scales. Specifically, at 12 weeks, HiSCR50 and IHS4-55 responses were achieved in 75.8% and 87.9% of patients, respectively. Relapse occurred in 33% at 6 months. Lower baseline IHS4, shorter disease duration, lower BMI, higher total inflammatory nodule and abscess count, absence of involvement of the pubis and genital area, and use of concomitant treatment were associated with better outcomes; only shorter disease duration remained significant on multivariate analysis (P < 0.022). Compared to results from other studies using standard regimens of regular-release doxycycline (RR-DC), MR-DC appears to have similar efficacy and more favorable safety profile. CONCLUSIONS: Low-dose MR-DC may be an effective short-term treatment or adjunctive therapeutic option for HS flares, with a reduced risk of AMR and adverse events.