Citrus red mite (Panonychus citri) is a common sensitizing allergen among children living around citrus orchards

Background: A recent investigation has suggested that Panonychus citri (cit rus red mite) is the most common causative allergen in citrus-cultivating f armers with asthma or allergic rhinitis. Objective: A cross-sectional survey was performed to evaluate the prevalenc e of asthma and sensitization to P. citri among children living around citr us orchards. Methods: A total of 1,055 children living around citrus orchards were enrol led. There were 544 boys and 511 girls with a mean age of 12.3 (range 7 to 16) years. They were evaluated by the ISAAC questionnaire, and a skin prick test with 13 common aeroallergens including P. citri and Japanese cedar po llen. Children who recorded ever having experienced wheezing on the questio nnaire were evaluated by methacholine bronchial provocation test and determ ined to have asthma if they showed bronchial hyperresponsiveness to methach oline simultaneously. Results: The positive skin test response to one or more inhalant allergens except P. citri was 35.5%, but when including P, citri, the positive respon se increased to 37.7%. The most common sensitizing allergens in the order o f decreasing frequency were Dermatophagoides pteronyssinus (26.6%), D. fari nae (22.7%), P. citri (14.2%), cockroach (11.3%), and Japanese cedar pollen (9.7%). Among the children without sensitization to house dust mites, the sensitization rate to P. citri was significantly higher in those 13 and ove r than in those under 12 (5.8% versus 2.5%, P < .05). The prevalence of ast hma was not different between the children with sensitization to P, citri a nd those without it (5.4% versus 4.0%, P > .05), although the prevalence wa s higher in those with sensitization to D. pteronyssinus or D. farinae than in those without sensitization to these allergens (7.9% versus 2.9%, P < . 05; 9.7% versus 2.6%, P < .05). Conclusion: Citrus red mite is a common sensitizing allergen among children living around citrus orchards. The features of sensitization and developme nt of asthma are different between citrus red mite and house dust mites.