Episodic angioedema associated with eosinophilia.

We studied four patients with recurrent attacks of angioedema, urticaria, and fever. During attacks, body weights increased up to 18 per cent, and leukocyte counts reached 108,000 per microliter (88 per cent eosinophils). The disease did not appear to threaten the function of vital organs. The two children received prednisone intermittently; the adults did not require treatment or were given alternate-day prednisone. Glucocorticoid therapy caused defervescence and diuresis and decreased total leukocyte and eosinophil counts. No patient had evidence of cardiac involvement (follow-up, 2 to 17 years). One patient remained in spontaneous remission for 20 years before symptoms recurred. Histologic studies showed that eosinophils localized and degranulated in the dermis, and they appeared to induce edema. Although this syndrome might be classified as a variant of the hypereosinophilic syndrome, we believe it is a separate entity because of its distinctive characteristics and its benign course.