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.