Food sensitization and food allergy in allergic Thai patients from a tertiary care center in Thailand.

Background: A skin prick test (SPT) and food challenge test (OFC) are useful in identification of food sensitization and food allergy.

Objective: To evaluate food allergen sensitization by SPT and food allergy by OFC in allergic Thai patients.

Methods: SPTs for common food allergens were performed on allergic patients at Siriraj Hospital, Bangkok, Thailand, from 2011 to 2015. An OFC was performed in positive food SPT patients with informed consent.

Results: SPTs to food were positive in 539 (20%) out of 2,678 allergic patients (73.8% were < 10 years old). Crab was the most common sensitized food in each year of the study period. In patients aged < 1 year, the most common sensitized foods were egg white (23.8%) and wheat (22.2%), while shrimp was for patients aged > 10 years (25%). A positive OFC was found in 29 (26.1%) out of the 111 OFCs performed (9.1% in patients with asthma, 28.6% in allergic rhinitis and 26.3% in food allergy). Positive OFCs were found for 60% of the crab, 35.7% of the egg yolk, and 31% of the cow's milk OFCs. Compared to OFC, SPT showed high specificity (71%-100%) but low sensitivity (0%-40%). The percentage of sensitization to egg white, egg yolk, wheat, soy, and peanut significantly increased (p < 0.05) from 2011 to 2015.

Conclusion: The sensitization to egg white, egg yolk, wheat, soy, and peanut significantly increased and crab was the most common sensitized food. Food allergy in patients with allergic rhinitis was as common as in patients diagnosed food allergy.