Interferon-gamma-induced local leukocytoclastic vasculitis at the subcutaneous injection site.

Cutaneous reactions associated with interferons (IFNs) treatment are either localized or generalized. The most common presentation of localized reactions at IFNs injection site is usually an erythematous patch or plaque. Local leukocytoclastic vasculitis presenting with cutaneous necrosis is extremely rare. We report a 19-year-old man with hepatitis B who had local leukocytoclastic vasculitis induced by interferon-gama injection at the injection site. After changing the injection sites and using the combined treatment of prednisone and colchicine, the previous lesion healed and no other cutaneous lesion occurred. We also made a mini review of such cases.