Prevalence and trends of sensitisation to aeroallergens in patients with allergic rhinitis in Guangzhou, China: a 10-year retrospective study

OBJECTIVE To investigate the prevalence and trends of sensitisation to common aeroallergens among outpatients with allergic rhinitis (AR) in Guangzhou, China, over the past decade. DESIGN A retrospective study; linear-by-linear association and simple linear regression were used to determine the trends in the prevalence of aeroallergen sensitisation. SETTING One grade-A hospital in Guangzhou, the largest city in southern China. PARTICIPANTS A total of 5486 patients (2297 males and 2489 females) who visited the ear, nose and throat outpatient clinic, from January 2005 to December 2014, were enrolled. All patients who presented with nasal hyper-reactive symptoms and who completed serological allergy testing, measuring specific IgE (sIgE) in the serum, were included. Among them, 4085 participants (2269 males and 1816 females) were diagnosed as being patients with AR. OUTCOME MEASURES Prevalence and trends of sensitisation to various types of aeroallergens were assessed. RESULTS The overall prevalence of sIgE-mediated sensitisation to aeroallergens in these patients with AR were as follows: 84.4% for house dust mites (HDMs), 23.4% for pet allergens, 21.1% for cockroaches, 9.1% for mould allergens, 7.7% for tree pollen and 6.0% for weed pollen. When all patients with nasal hyper-reactivity were stratified by decade of age, increasing age was associated with a decrease in sIgE positivity by ∼5.13% (95% CI -7.28% to -2.98%, p<0.01). Within the past decade, the prevalence of sensitisation to pet allergens in patients with AR increased at an annual rate of 1.3% (95% CI 0.85% to 1.67%, p<0.01). CONCLUSIONS This study demonstrated that HDMs comprised the most common aeroallergen in Guangzhou. The prevalence of sensitisation to aeroallergens decreased with increasing age. During the past decade, the prevalence of sensitisation to pet allergens showed an upward trend, suggesting an urgent need for its prevention and treatment.