Antineutrophilic Cytoplasmic Antibody Positive Vasculitis Associated with Methimazole Use

Abstract

ANCA-associated vasculitis (AAV) is a rare and potentially life threatening complication associated with antithyroid drug use. It is more commonly reported with propylthiouracil, with fewer cases reported with methimazole use. We present the case of a 55-year-old man with toxic multinodular goiter which was treated with methimazole for 6 months. He developed ANCA positive leukocytoclastic vasculitis with hemorrhagic and necrotic bullous lesions of lower extremities. The vasculitis was initially thought to be secondary to recent cephalosporin use; however, the skin lesions progressed despite stopping the cephalosporin and treatment with steroids, and he developed osteomyelitis. His vasculitis resolved after cessation of methimazole use. This case highlights the importance of careful monitoring for variable manifestations of AAV in patients treated with methimazole.

Methimazole-Induced Leukocytoclastic Vasculitis: A Case Report

“…Kawachi et al [10] reported the first case of MMI-induced antineutrophil cytoplasmic antibodies (ANCA)-associated cutaneous vasculitis in 1995. The following cases confirmed the validity of the proposed pathogenesis which is related to the stimulation of a particular immune processes, leading to the production of ANCA [11, 12, 13, 14, 15, 16]. However, Kanat et al [17] reported a case with recurrent hyperthyroidism who developed ANCA-negative cutaneous small-vessel vasculitis after taking MMI (20 mg daily) for 1 week.…”

“…It is also interesting to note that most cases with MMI-induced leukocytoclastic vasculitis took many months to develop after the initiation of the medication. However, this is only true in individuals with no history of PTU exposure [12, 13]. In contrast, 4 reported cases [11, 14, 15, 17], who had a history of prior PTU administration, developed MMI-induced cutaneous vasculitis over a shorter period of exposure (i.e., approximately 1 week).…”

A Leukocytoclastic Vasculitis Case Due to Tenofovir Use

“…Small-vessel vasculitis are evaluated under two headings either antineutrophil cytoplasmic antibody (ANCA) positive or ANCA negative. These antibodies are autoantibodies that target lysosomal enzymes of neutrophils and grouped as c-ANCA that is against proteinase, and p-ANCA that is against myeloperoxidase [4]. ANCA positive small-vessel vasculitis are classified under four groups as microscopic polyangiitis, Wegener's granulomatosis, Churg-Strauss syndrome, and drug-induced vasculitis [5].…”

Painful Ulcerative Lesions on Bilateral Lower Extremities

“…2 In parallel, reports of methimazole-associated vasculitis have increased, with clinical manifestations ranging from cutaneous ulcers to pulmonary hemorrhage. [3][4][5][6][7][8][9] The incidence of ANCA-positive propylthiouracil-associated vasculitis is reportedly 39.2 times higher than in patients receiving methimazole. 3 Hydralazine, minocycline, and propylthiouracil are commonly prescribed medications known to cause positive ANA, P-ANCA, and MPO-ANCA test results, and vasculitic skin, kidney, and lung disease.…”

“…1,10 Cutaneous lesions include maculopapules, vesicles, purpura, bullae, and ulcers on the lower extremities, with hemorrhage and/or necrosis. 1,[4][5][6][7][8][9][10] Clinicians should exclude more common causes of these skin lesions, including infections, neoplasms, and primary vasculitides, and must be aware that drug-induced vasculitis can occur after several years on a medication. 1 One should perform an ANCA test and obtain a skin biopsy specimen for histologic evidence of vasculitis.…”