Leukocytoclastic vasculitis: a rare manifestation of propylthiouracil allergy

To report a case of leukocytoclastic vasculitis as a manifestation of propylthiouracil allergy.

We present the history, findings on physical examination, and results of laboratory evaluation in a 25-year-old woman. Associated reports from the literature are reviewed.

The patient, with a history of Graves' disease, was referred for evaluation of a purpuric rash on the pinnas and buttocks bilaterally. Findings included exophthalmos and bilateral goiter with neck bruits. She was biochemically hyperthyroid. Biopsy of the skin lesions revealed leukocytoclastic vasculitis. Propylthiouracil therapy was discontinued, and prednisone was prescribed. Treatment with radioactive iodine resulted in appreciably diminished skin lesions and reduction in the size of the thyroid gland, but thyroxine and triiodothyronine levels increased. Administration of a second, higher dose of radioactive iodine with concomitant lithium carbonate resulted in clinical and biochemical improvement. Six months after initial assessment, the rash had resolved, and the patient's free thyroxine value had normalized, although the thyrotropin level was still suppressed.

Leukocytoclastic vasculitis, although rarely seen as a manifestation of propylthiouracil allergy, has been reported in the medical literature and should be considered in the differential diagnosis of patients with a vasculitic rash. Treatment consists of discontinuation of the offending medication and administration of a corticosteroid and, occasionally, cyclophosphamide or plasmapheresis.