Urticaria and angioedema: diagnosis and evaluation.

Abstract

Because urticaria clears spontaneously in most patients, an extensive workup is not advised during the early weeks of an urticarial eruption. Whether and when to perform a screening workup or a more extensive workup depend on the degree of suspicion that the patient is ill, the urgency with which the patient presses for an answer, and the presence or absence of signs or symptoms that might lead the physician to pursue a diagnosis other than chronic idiopathic urticaria. Angioedema may occur with urticaria, and when it does, the prognosis is worse. Whereas urticaria manifests as circumscribed edema involving the superficial dermis, angioedema involves primarily the deep dermis or subcutaneous or deeper layers. Individual urticarial lesions usually disappear within 2 to 4 hours, whereas those of angioedema can persist for 72 hours. The workup for patients with chronic angioedema can be similar to that for patients with urticaria. However, several additional diagnostic possibilities should be pursued in patients with angioedema, such as hereditary angioedema caused by C1-esterase inhibitor deficiency, because anabolic steroids are effective in the treatment of these conditions.