A case paradoxical hidradenitis suppurativa (HS) with janus kinase inhibitor, literature review and pooled analysis of biological agent-induced HS.

Hidradenitis suppurativa (HS) is a debilitating chronic inflammatory skin disease. Biological therapy has revolutionized it's the treatment. Paradoxical HS occur with various biological and targeted agents. We report a patient with juvenile rheumatoid arthritis who developed HS after 6 months of tofacitinib therapy. A comprehensive literature review identified 43 cases of paradoxical HS among patients on biological and targeted agents. Pooled analysis of the cases showed Crohn's disease 18(41.8%) and RA 9(20.9%) as commonest indications for biological therapy. Adalimumab 20(46.5%) followed by infliximab 9(20.9%) were the commonest offending agent. Duration of biological treatment prior to HS manifestation was 12(1-120) months. Smoking 21(48.8%) and overweight or obese 20(46.5%) were most frequent HS risk factors. Fourteen (32.6%) patients had a second paradoxical event, 11(25.6%) developed psoriasis and 4(9.3%) Crohn's disease. Presence of ≥1 risk factor for HS, continuation of the implicated biological agent and occurrence of more than one paradoxical event were factors associated with poor paradoxical HS outcome. This article is protected by copyright. All rights reserved.