Many individuals believe that food allergies are limited to childhood and remain stagnant throughout adulthood. However, recent studies have shown that it is indeed possible for adults to develop food allergies later in life. Preschoolers are more susceptible to food allergies, with a higher likelihood of outgrowing them as they age. According to the Australian National Allergy Council, one in 50 adults suffer from food allergies. On the contrary, a US survey suggested that up to one in ten adults developed food allergies in adulthood. These allergies are immune responses mediated by immunoglobulin E (IgE), which is crucial in triggering allergic reactions.
Adults can develop a variety of IgE-mediated food allergies, ranging from common to rare. In a US survey, the most prevalent food allergies among adults were to shellfish, cow’s milk, peanuts, tree nuts, and fin fish like barramundi, snapper, salmon, cod, and perch. Surprisingly, approximately 45% of adults reported reacting to multiple foods, indicating a complex immune response in adulthood. This contrasts with most common childhood food allergies, such as cow’s milk, egg, peanuts, and soy. Overall, adult food allergy prevalence seems to be on the rise, with peanut allergy alone seeing a three-fold increase since 2003. Additionally, tree nuts and fin fish allergies have doubled, while shellfish allergies remain stable.
While new adult-onset food allergies are becoming more prevalent, childhood-initiated food allergies are also more likely to persist into adulthood. Several factors contribute to this phenomenon, including low vitamin D levels, lack of immune system challenges, allergen avoidance, and increased antibiotic use. One of the rare but noteworthy adult-onset food allergies is tick-meat allergy, also known as α-Gal syndrome. This allergic reaction to galactose-alpha-1,3-galactose is triggered by tick bites and can cause a lifelong allergy to red meat. Additionally, fruit-pollen allergy, or pollen food allergy syndrome, can provoke allergic reactions in susceptible adults when consuming certain fruits, vegetables, and herbs due to pollen cross-reactivity.
Another unique allergic condition that adults may experience is food-dependent exercise-induced allergy. This rare allergy occurs when food molecules trigger an IgE reaction during physical activity, leading to symptoms ranging from hives to anaphylaxis. Common trigger foods include wheat, seafood, meat, poultry, eggs, milk, and nuts. Surprisingly, allergic reactions can occur with lower levels of exposure to trigger foods, exacerbated by factors like NSAID use, alcohol consumption, or sleep deprivation. While this allergy is rare, those affected often have other allergic conditions like hay fever, asthma, and dermatitis.
As the prevalence of adult food allergies continues to rise, it is crucial to take these allergies seriously. The burden on physical health, psychological well-being, and healthcare costs is significant. Individuals with severe food allergy symptoms should carry an adrenaline auto-injector pen and wear medical information bracelets. Unfortunately, surveys suggest that only a quarter of adults with food allergies have access to an adrenaline pen. If you suspect you have an IgE-mediated food allergy, consult your healthcare provider to develop a comprehensive management plan. Allergy and Anaphylaxis Australia provides valuable resources for further information on managing adult food allergies.