Features of allergens in patients with allergic diseases in Chongqing，China

Abstract:

Objective：To investigate the features of inhaled allergens in patients with allergic diseases in Chongqing，China，and to optimize the number and type of inhaled allergens used for skin prick test（SPT）. Methods：SPT was performed for 2305 patients sus－pected of having allergic diseases who visited Department of Allergy in Chongqing People’s Hospital from September 2014 to August 2016，and their results were analyzed. The distribution characteristics of inhaled allergens were described according to age and season，and then the combination of allergens for SPT was optimized to cover at least 95% of patients with positive allergens. Results：Of all 2 305 patients，1 672（72.54%） had at least one positive skin prick reaction. The six most common allergens identified by SPT were Dermatophagoides farina（62.00%），Dermatophagoides pteronyssinus（58.61%），cockroach（28.81%），cat hair（14.62%），Humulus （14.45%），and mugwort（14.27%）. Among the patients with grade（+++） positive inhaled allergens or above，Dermatophagoides farina had a positive rate of 77.75% and Dermatophagoides pteronyssinus had a positive rate of 76.24%，which were significantly higher than the positive rate of other allergens. The overall positive rate of allergens was 67.81% in spring，72.63% in summer，78.78% in autumn，and 72.09% in winter，and there was a significant difference between seasons（χ2=17.741，P=0.000）. The positive rate of dust mite showed a similar seasonal change trend as the overall pos－itive rate of allergens. The patients aged ≤17 years，18-39 years，40-59 years，and ≥60 years had overall positive rates of aller－gens of 82.31%，73.78%，64.77%，and 54.97%，respectively，and there was a significant difference between these age groups（χ2=65.456，P=0.000）；the positive rate of inhaled allergens decreased with the increase in age. SPT with four inhaled aller－gens（Dermatophagoides farina，cockroach，Dermatophagoides pteronyssinus，and Humulus） was sufficient to identify ≥95% patients with positive allergens among the patients with suspected allergic diseases in Chongqing. Conclusion：Dermatophagoides farina and Dermatophagoides pteronyssinus are the most common inhaled allergens in patients with allergic diseases in Chongqing. The positive rate of inhaled allergens is affected by age and season and shows a certain trend. SPT with four inhaled allergens can identify most patients with positive inhaled allergens and can be used as the economic and effective allergen combination for the epidemiological survey of inhaled allergens in patients with allergic diseases in Chongqing.