Background: Allergic rhinitis is commonly found in Thailand and its prevalence seems to be higher in each area with the commonly found allergens and different characteristics of the population.
Objective: To study the prevalence of each type of allergen from a skin prick test carried out among patients with allergic rhinitis in HRH Princess Maha Chakri Sirindhorn Medical Center (MSMC), Nakhon Nayok Province, Thailand.
Materials and Methods: The study was conducted using a descriptive cross-sectional study design. Retrospective data were collected from the medical records of all patients with allergic rhinitis who took a skin prick test at the Department of Otolaryngology, MSMC between 1 April 2016 and 31 March 2021. The results of the prevalence of allergens were reported in terms of numbers and percentages. Skin prick tests giving positive results among patients with allergic rhinitis were compared to the test results of patients with allergic rhinitis and asthma.
Results: In total, 304 subjects diagnosed with allergic rhinitis who took a skin prick test met the criteria for inclusion in the present study, 207 were female (68.09%). Their mean age was 39.65+12.32 years old. The study found that 198 (65.13%) patients had positive results from of the test. The standardized mite mix was the most common allergen (55.92%), followed by American cockroach (37.82%), Johnson grass (5.59%), mixed Aspergillus (3.95%), and dog epithelium (1.32%). The patients with allergic rhinitis and asthma had a higher incidence of positive results than the patients with allergic rhinitis alone (risk difference was 13.36%, 95% CI 5.06 to 21.66, p-value = 0.005).
Conclusion: The present study revealed that the prevalence of a positive skin prick test response was 65.13% of patients diagnosed with allergic rhinitis. The standardized mite mix was the most frequently found allergen, followed by American cockroach, Johnson grass, mixed Aspergillus, and dog epithelium.

Keywords: Skin test; Allergens; Allergic rhinitis; Prevalence