Association between skin prick test and serum specific immunoglobulin E to American cockroach allergens in allergic rhinitis patients.

INTRODUCTION AND OBJECTIVES: American cockroach is a common aeroallergen sensitization in allergic rhinitis (AR) patients. Association between skin prick test (SPT) and specific immunoglobulin E (sIgE) to American cockroach allergen remains uncertain. This study aimed to evaluate the association between SPT and sIgE to American cockroach allergen in patients with AR. MATERIALS AND METHODS: This cross-sectional study was conducted in Thai AR patients aged 6-25 years from September 2013 to October 2014. SPT and sIgE to American cockroach allergen were performed and the correlation was calculated using SPSS Statistics version 18. RESULTS: Sixty-seven AR patients, with median age of 15 years were included in this study. SPT and sIgE to American cockroach allergen showed a positive result in 68.7% and 58.2% cases, respectively. Positive SPT or positive sIgE to American cockroach was found in 79.1%. Thirty-two patients (47.8%) tested positive for both SPT and sIgE to American cockroach allergen. Fourteen from a total of 67 cases (20.9%) with negative sIgE had positive SPT to American cockroach, while seven cases (10.4%) with negative SPT had positive sIgE to American cockroach. Moderate correlation was observed between mean wheal diameter (MWD) and sIgE level to American cockroach (r=0.465, p=0.001). No significant correlation was found between MWD of SPT or sIgE level to American cockroach and AR severity. CONCLUSION: A moderate correlation was observed between MWD of SPT and sIgE level to American cockroach. If SPT is negative in allergic rhinitis patients highly suspected of having American cockroach allergy, serum sIgE should be considered and vice versa.