Prevalence of food allergies in young adults and their relationship to asthma, nasal allergies, and eczema.

BACKGROUND

The true prevalence of food allergy in adults is generally thought to be uncommon. It is unknown whether there are any relationships between food allergy and atopic diseases.

OBJECTIVE

To determine the prevalence of probable immunoglobulin (Ig)E-mediated food allergy to peanut, shrimp, cow's milk, wheat, and egg as defined by a positive skin prick test result and relevant clinical history to the same food, and to explore the relationship with atopic diseases.

METHODS

Cross-sectional epidemiologic study. One thousand one hundred forty-one randomly selected young adults (aged 20 to 45 years) underwent skin prick testing to five common food allergens (cow's milk, peanut, egg white, shrimp, and wheat), completed a detailed questionnaire, including validated items on respiratory symptoms, history of asthma and other allergic conditions, as well as undergoing lung function testing.

RESULTS

Just over one percent (1.3%, n = 15) had probable IgE-mediated food allergy. The prevalence of probable IgE food allergy was: <0.27% for wheat, 0.09% (95% confidence interval = 0.0 to 0.49%) each for cow's milk and egg, 0.53% (0.21 to 1.09%) for shrimp, and 0.61% (0.25 to 1.26%) for peanut. Those with probable IgE peanut and shrimp allergy were significantly more likely to have current asthma and doctor-diagnosed asthma. Wheeze and history of eczema were also associated with peanut allergy, whereas nasal allergies were associated with shrimp allergy.

CONCLUSIONS

The prevalence of probable IgE-mediated food reactions is rare in young adults. Some positive associations between probable IgE-mediated food allergy and allergic diseases were found, but larger study numbers are required to confirm these results.