Leukocytoclastic vasculitis: a rare manifestation of propylthiouracil allergy.
OBJECTIVE
To report a case of leukocytoclastic vasculitis as a manifestation of propylthiouracil allergy.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Section of Endocrinology, Diabetes, and Metabolism, Lahey Clinic Medical Center, Burlington, Massachusetts 01805, USA.
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Perez
D000328:Adult; D013956:Antithyroid Agents / Q000276:immunology* / Q000627:therapeutic use; D005260:Female; D006111:Graves Disease / Q000188:drug therapy; D006801:Humans; D006967:Hypersensitivity / Q000150:complications* / Q000276:immunology*; D011441:Propylthiouracil / Q000276:immunology*; D018366:Vasculitis, Leukocytoclastic, Cutaneous / Q000209:etiology* / Q000473:pathology
D013956:Antithyroid Agents; D011441:Propylthiouracil