The incidence of food allergy is increasing in India and south-east Asia. The most common food allergies are milk, egg, soy, wheat, fish, shellfish, peanut and tree nuts. Peanut and tree nuts are common food allergies in both children and adults. Peanuts are legumes or plants, not nuts, contrary to the name. The common tree nuts leading to allergies are walnut, almond, hazelnut, pecan, cashew and pistachio.
What are the common symptoms of nut allergy?
The symptoms of nut allergy are variable from very mild symptoms to severe and life threatening reactions like anaphylaxis. The symptoms of nut allergy usually start within minutes to an hour of ingestion of nuts or any food containing nuts. The common symptoms are tummy pain, cramps, nausea, vomiting and loose motions. There can be swelling of the lips, tongue, eye or face, hives or urticaria and angioedema. Some people can have a runny nose, cough, shortness of breath and difficulty breathing. Anaphylaxis is a life-threatening allergy reaction where the person has severe difficulty in breathing, low blood pressure and a weak pulse. Anaphylaxis is a medical emergency.
How do we make a diagnosis of nut allergy?
An accurate diagnosis of peanut and tree nut allergy is essential. This usually requires a detailed medical history, details of any previous allergic reactions and about any family history of allergies. Allergy tests are required to confirm a diagnosis of nut allergy. This can be in the form of a skin prick test (SPT) or blood tests (immunocap). These tests determine the presence of allergen-specific immunoglobulin E against the particular nut leading to allergy symptoms. In some children where the results are inconclusive we may need to perform an oral food challenge test. Oral food challenge requires a child to be fed small amounts of the suspected allergy-causing food in increasing doses over a period of time, under strict supervision of an allergist. As this test sometimes can lead to an allergy reaction it is recommended to perform this in a hospital setting.
Does nut allergy go away?
It has been seen that approximately 15-20 percent of children with peanut allergies outgrow them. Tree nut allergies are tougher to outgrow and are often lifelong.
What food needs to be avoided if a person is allergic to nuts?
As with most food allergies, the best way to avoid an allergic reaction is to avoid eating the offending nuts. As nuts might appear similar after being broken it is often recommended to avoid all nuts when eating out. Parents need to inform the day care, nursery and school regarding any nut allergy. Reading labels is important to check the ingredients in various processed food items like desserts, ice creams, cakes and baked foods.
If a child is allergic to one nut can he take any other nut?
Children allergic to a particular nut may be able to tolerate other tree nuts. This requires careful testing with skin prick tests or blood tests and sometimes requires an oral food challenge.
If you or your child are suffering from a suspected or confirmed nut allergy you need to contact an allergist for proper evaluation and management guidance.