Cashew belongs to the tree nut family that includes pistachio and mango. Along with walnut, almond and other tree nuts, cashew allergy is one of the most common food allergies in children and adults. Like peanut, cashew can cause the most severe allergic reactions, even if a person is exposed to small amounts. Cashew cross-reacts with pistachio, so people who have cashew allergy tend to have an allergic reaction to pistachio. Cashew is a hidden ingredient in common foods, such as Asian meals, ice cream, cakes and as substitute for pine nuts in pesto sauce. People are seldom allergic to cashew alone, and contamination in the processing of nuts is so common that allergists often advise patients to avoid all tree nuts if cashew allergy has been diagnosed.
Hives and Swelling
Hives and swelling are the mildest allergic reactions to cashew. Initially, there may be itching or tingling in or around the mouth within minutes of eating or touching cashew or food with cashew ingredients. Raised, red, itchy welts of various sizes may appear at random on the skin surface. Swelling below the skin surface, called angioedema, may also occur on exposure to cashew. Hives and swelling usually resolve within a day or two.
Gastrointestinal Symptoms
People allergic to cashew may immediately experience stomach cramps or vomiting as the body attempts to expel the offending food. More severe symptoms may include diarrhea, projectile vomiting, difficulty swallowing or nausea. A swollen tongue or throat may block the airways or may indicate swelling inside the digestive tract.
Respiratory Symptoms
An allergic reaction to cashew may elicit symptoms of hay fever or asthma when airborne cashew nut allergens are inhaled. Runny or stuffy nose, itchy eyes, nose, roof of the mouth and coughing are common symptoms of an allergic reaction in the nasal passages. Wheezing or whistling sounds heard on breathing out is a sign of constricted airways. Other symptoms of an asthma attack due to cashew allergy may include shortness of breath, tightening of the chest and chest pains.
Anaphylaxis
Cashew causes a severe allergic reaction called anaphylaxis. Symptoms include rapid pulse, swelling of the throat that prevents breathing, constriction of the airways, fainting, lightheadedness and loss of consciousness. Ingestion or inhalation of even small amounts of cashew may elicit an anaphylactic shock. Anaphylaxis develops suddenly and becomes life-threatening quickly, so it is important to seek immediate medical attention.
