Urticarial Vasculitis Induced by Adalimumab Biosimilar in an Elderly Female With Hidradenitis Suppurativa: A Case Report.

Urticarial vasculitis (UV) is a type of small-vessel vasculitis, which is rarely associated with anti-tumor necrosis factor (TNF)-alpha medication. We describe a 72-year-old woman with multiple comorbidities on several medications, including an adalimumab biosimilar for Hurley stage II recalcitrant hidradenitis suppurativa (HS), who presented with new-onset severe angioedema and a rash with urticarial wheals that covered most of her body surface area. The diagnosis of drug-induced UV is supported by both the history of adalimumab biosimilar use and the histopathology result. The patient responded successfully to a course of doxycycline administered for three months, which was preceded by corticosteroid dosages, both orally and intravenously, to reduce inflammation. The given case highlights the correlation between a distinct dermatologic autoimmune manifestation and TNF-targeted therapy, demonstrating the importance for dermatologists to be aware of the potential side effects of adalimumab biosimilars in order to manage them effectively.