Systemic adverse effect of antithyroid drugs

Antithyroid drugs adverse effects are varied and rare. Autoimmune disorders (vasculitis, lupus erythematosus, polyarthritis...) are unusual and seriou s complications of antithyroid drugs. Since 1945, fewer than 100 cases of s ystemic manifestations related to antithyroid drugs have been reported in t he literature, most frequently with propylthiouracil. The outcome is usuall y good after drug discontinuation, but some fatal cases have been reported. Because possible cross-sensitivity with other antithyroid drugs, the appro priate treatment for hyperthyroidism relapse if a patient has had an antith yroid drug adverse reaction, should be 131I-Iodine or surgery. We report fo ur new cases of systemic manifestations during propylthiouracil therapy.