Aeroallergen Skin Prick Test Reactivity Lacks Seasonal Variation in Riyadh Region.

Abstract

Background:-Exposure to aeroallergens varies in different seasons and correlates with increased frequency of sensitized individuals seeking medical aid. Objectives:-Based on skin prick reactivity during each calendar month of the year the reactivity pattern of aeroallergens was assessed. Methods:-This was a retrospective analysis of data of 238 patients (165 female and 73 male; mean age 26+11 years) with airway allergy undergoing skin prick testing between 2014 and 2016 at King Khalid University Hospital, Riyadh. A wheal diameter measuring 3 mm or more was considered as a positive reaction. Results:-Among the individuals tested there were 98 (41.1%) patients with asthma, 115 (48.3%) had rhinitis and 25 (10.5%) were suffering from hay fever. The most frequently reacting indoor aeroallergen was cat in 120 (50.2%) patients followed by Dermatophagodies farinae in 78 (32.6%), Dermatophagodies pteronyssinus in 67 (28%) and Aspirgillus in 57 (23.8%). Among the outdoor aeroallergens cynodon dactylon reactivity was observed in 90 (37.6%) patients followed by salsola kali in 86 (36.2%) and lolium perenne in 83 (34.7%). Reactivity against the cat allergen was consistently higher than the house dust mite allergens peaking in October until the month of March. Reactivity pattern of salsola kali, cynodon dactylon and lolium perenne was almost similar and remained higher than the other pollens between the months from September to May. Data for the months of July and August were not available. Conclusion:-Skin prick test reactivity against aeroallergens was not only high in Riyadh region but was also devoid of seasonal variations.