Association of body mass index and season with histamine skin reactivity in Chinese children with allergic rhinitis.

BACKGROUND: To investigate the association between histamine skin reactivity and body mass index (BMI) and other clinical factors, 526 children (3-6 years old) who underwent a skin-prick test (SPT) to diagnose allergic rhinitis were enrolled.

METHODS: The SPT was carried out using 43 common allergens (commercial kit). The wheal size was analyzed. The associations between histamine reactivity and age, gender, BMI, atopy, parental smoking history, and testing season were examined.

RESULTS: Mean age was 4.6 ± 1.1 years. Among all 526 children, 202 (38.4%) had intermittent allergic rhinitis (IAR), 164 (32.1%) had IAR + persistent allergic rhinitis (PER), and 160 (30.4%) had PER. The size of the histamine skin wheal and maximum diameter for positive allergens showed significant seasonal differences (P = 0.001 and P = 0.02, respectively). Children with biparental allergy history had a higher BMI (P = 0.006). BMI (P < 0.001), summer testing (P = 0.001), and autumn testing (P < 0.001) were independently associated with the size of the histamine skin wheal. Only winter testing was independently associated with the maximal diameter for positive allergens (P = 0.002).

CONCLUSIONS: Higher histamine skin reactivity was associated with higher BMI and summer or autumn testing. Subject BMI and season should be considered for better interpretation of the SPT. The mechanisms underlying these associations require further study.