Utility of routine laboratory testing in management of chronic urticaria/angioedema.

BACKGROUND: Laboratory tests are routinely ordered to identify or rule out a cause in patients with chronic urticaria/angioedema (CUA). The results of these tests are usually within normal limits or unremarkable. OBJECTIVE: To investigate the proportion of abnormal test results in patients with CUA leading to a change in management and in outcomes of care. METHODS: Retrospective analysis of a random sample of adult patients with CUA from 2001-2009. RESULTS: Cases totaled 356: 166 with urticaria and angioedema (AE), 187 with urticaria, and 3 with only AE. Patients were predominately women (69.1%) and white (75.6%), with a mean age of 48 ± 15 years. Abnormalities were commonly seen in complete blood counts (34%) and in complete metabolic panels (9.4%). Among the 1,872 tests that were ordered, results of 319 (17%) were abnormal. Of 356 patients, 30 underwent further testing because of abnormalities in laboratory work. This represented 30 of 1,872 tests (1.60%). Only 1 patient benefited from a subsequent change in management. CONCLUSIONS: Laboratory testing in CUA patients referred for an Allergy and Immunology evaluation rarely lead to changes in management resulting in improved outcomes of care.

Duke Scholars

Author Cristine Radojicic Medicine, Pulmonary, Allergy, and Critical Care Medicine