Patch testing plays a role in management of chronic urticaria

Abstract

Background. Chronic urticaria (CU) is one of the most challenging and frustrating therapeutic problems faced by a dermatologist. This study was done to clinically evaluate patients of urticaria presenting with symptoms of more than 6 weeks duration and to estimate the practicality of doing patch testing in chronic urticaria. Methods. A total of 160 patients of CU were included in the study. After evaluating with history, clinical examination and investigations sixty five patients were patch tested with Indian standard and cosmetic series. Results. Physical urticaria was prevalent in 16.87% patients, infectious etiology in 14.37% patients, food and intestinal infestation in 5% of patients each, drugs and inhalants in 3.75% each, systemic disease in 2.5% patients and due to insect bite in one patient (0.62%). Of the seventy seven patients in whom no suspected cause could be arrived at, sixty five patients consented for patch testing, twenty four (36.9%) yielded positive results and on follow up with avoidance of suspected allergen, eleven (16.92%) had complete remission. Conclusions. Patch test is a safe, simple and inexpensive test that can be included among the battery of diagnostic investigations for CU since it allows effective diagnosis and management of a relevant number of patients. More allergens can be included to widen the coverage of offending allergens.