Paradoxical hidradenitis suppurativa in Crohn's disease patients receiving infliximab: a case report and review of literature.

The introduction of TNF blockers in the therapeutic armamentarium of inflammatory bowel diseases (IBD) has largely advanced the way by which clinicians manage these disorders. However, some patients develop de novo immune-mediated diseases during the treatment. We here present the case of paradoxical hidradenitis suppurativa, a chronic inflammatory skin disease characterized by the development of recurrent nodules and abscesses in intertriginous areas, in a 20-year-old, nonsmoker, normal-weight women, with no family history of hidradenitis suppurativa or IBD, diagnosed with nonstricturing nonpenetrating ileocolonic Crohn's disease in 2013, during treatment with infliximab. Infliximab discontinuation was followed by a significant improvement of skin lesions. We also discuss 22 additional cases of paradoxical hidradenitis suppurativa in IBD patients on TNF antagonists reported in the literature with the aim to identify potential risk factors for the development of such a complication. All the patients had Crohn's disease, and the majority of them were women (19/23; 82.6%). All cases occurred during therapy with anti-TNF agents [14/23 (61%) patients were treated with adalimumab and 9/23 (39%) patients were treated with infliximab]. The therapeutic approach directed at maintaining/holding the undergoing biologic therapy is still uncertain. Further studies are needed to determine the most appropriate treatment choice toward ongoing biologic therapy.