Leukocytoclastic Vasculitis Associated with Adalimumab Therapy for Crohn's Disease.

Leukocytoclastic vasculitis (LCV) is rarely associated with anti-tumor necrosis factor [TNF] α therapy. We report a 22-year-old man with new onset of a pustular rash on his bilateral upper and lower extremities while on adalimumab therapy for Crohn's disease. Skin biopsy of the affected area showed perivascular extravasation of erythrocytes, neutrophils, eosinophils and vascular damage surrounding blood vessels associated with fibrin, consistent with LCV. Patient was treated with topical steroids and subsequently transitioned to ustekinumab therapy with follow-up colonoscopy showing minimal active disease. Our report highlights the association of a unique dermatologic autoimmune manifestation with TNF-targeted therapy in a patient with Crohn's disease.