Skin Prick Test with Aeroallergens in Patients with Chronic Urticaria

Aeroallergens induce exacerbation of chronic urticaria. Skin prick test is a suitable test for detection of immediate reaction. The aim of this study was to detect the incidence of positive skin prick test to aeroallergens in patients with chronic urticaria. This cross-sectional study was done on patients with chronic urticaria during three years. After taking history and physical examination of patients, laboratory tests including: CBC-diff, ESR, stool exam, thyroid test, CH50, C3, C4, IgE, ANA, simple urinary test, AST and ALT were done. We used aeroallergens including: Timothy, Bermuda, Maple, Nettle, Feather, Aspergillus, Alternaria, Cockroach, Grass mixed, Ash, Alder, Russian Thistle, Pigweed, Dermatophagoides Farinae, Dermatophagoides pteronyssinus with negative and positive tests on the forearm. The result was evaluated. From 78 cases with chronic urticaria, 23 (30%) were male and 55 (70%) were female. Their age was between 7 to 50 years old and the mean age was 30.43±11.27 years. Twelve (15%) patients had positive skin prick test to 9 allergens that 8 (10%) were male and 4 (5%) were female. Among positive skin prick tests, 9 of 25 cases were related to Dermatophagoides pteronyssinus (DP) (36%) and 9 cases were related to Dermatophagoides farinae (DF) (36%). The results showed that mites are more common in chronic urticaria.