Prevalence of oral allergy syndrome among school-age children in Mexico: a first nationwide study in Mexico and Latin America.

BACKGROUND

Epidemiological knowledge about oral allergy syndrome (OAS) in Latin America is limited. The aims of this study are to estimate the prevalence of OAS in Mexican children, identify the most associated foods, describe its main clinical manifestations, and determine the associated factors.

MATERIAL AND

METHODS

Multicenter cross-sectional study (October 2023-April 2024) with stratified sampling in 8 regions of Mexico. A structured questionnaire was applied and multivariate analyses were performed to identify factors associated with OAS.

RESULTS

A total of 4269 children were included (51.7% boys; mean age: 8.7 years). The national prevalence of OAS was 2.8% (95% confidence interval (CI): 2.3%-3.3%), with higher frequency in the northwest (6.4%), southeast (3.9%), and southwest (3.6%) regions. In addition to oral manifestations, the most frequently reported manifestations were reddish skin (40.8%), hives (39.2%), skin itching (38.3%), and sneezing (26.7%). The foods most frequently associated with OAS were milk (21.7%), shrimp (10.8%), egg (7.5%), avocado (6.7%), cashew, wheat, and peanut (5.8% each), tomato, and pork (4.2% each). Age 9-12 years (adjusted odds ratio [OR]: 1.63; P = 0.013). Asthma (adjusted OR: 1.88; P < 0.001), atopic dermatitis (adjusted OR: 3.09; P < 0.001), and pollen allergy (adjusted OR: 4.25; P < 0.001) were significantly associated with OAS.

CONCLUSIONS

The prevalence of OAS in school-age children is nearly 3%. Multiple foods capable of causing oral manifestations were identified, with dairy, shrimp, and fish among the most important ones.