[Two cases of minocycline-induced vasculitis]

We report two cases of drug-induced vasculitis subsequent to long-term minocycline therapy. Case 1; A 27-year-old woman, who was receiving minocycline hydrochloride for eosinophilic pustular folliculitis of 68-months'duration, showed polyarthralgia, intermittent low-grade fever, and light red reticulated erythemas with subcutaneous nodules on her extremities. Case 2; A 31-year-old man developed reddish-brown, reticulated erythemas with induration on bilateral lower legs after 24-months' duration of minocycline hydrochloride treatment for hidradenitis suppurativa. In both cases, skin biopsies demonstrated vasculitis affecting a small-sized artery at the border of the dermis and subcutis. Serum antineutrophil cytoplasmic antibodies (ANCA) showed borderline elevation. In both cases cessation of minocycline administration resulted in rapid improvement of cutaneous lesions and constitutional symptoms. Recently, attention has been focused on drug-induced ANCA-positive vasculitis. Accumulation of previous case reports of minocycline-induced vasculitis with cutaneous lesions disclosed that the duration of the treatment before clinical symptoms averaged 35 months. Patients may present with livedoid skin lesions accompanied by fever, polyarthritis, autoimmune hepatitis and drug-induced lupus. Early recognition of ANCA-positive vasculitis is essential during long-term minocycline treatment, because cessation of the drug can result in complete resolution.