POTASSIUM-IODIDE SENSITIVITY IN 4 PATIENTS WITH HYPOCOMPLEMENTEMIC VASCULITIS

During metabolism studies of radiolabeled proteins in 126 participants 4 patients were suspected of being sensitive to potassium iodide (KI) because they repeatedly developed urticaria and other symptoms after KI administration. Two of the 4 patients suspected of KI sensitivity and 10 control patients were orally challenged with KI to document and characterize KI sensitivity and to evaluate the possible association(s) of KI sensitivity with urticaria, hypocomplementemia, and vasculitis. The KI challengesin the 2 sensitive patients precipitated urticaria, angioedema, polymyalgias, conjunctivitis, and coryza. One of these 2 patients also developed a severe systemic illness characterized by fever, headache, peritonitis, episcleritis, and pneumonitis. The 4 sensitive patients were strikingly similar in that they exhibited hypocomplementemia and dermal vasculitis associated with chronic urticaria or systemic lupus erythematosus, suggesting that other patients with similar clinical features may be sensitive to KI and that KI may precipitate severe systemic illness in them.