When people think of nut allergies, they tend to think of peanuts. In fact, a sizable number of people are allergic not to peanuts (which are actually a legume) but to tree nuts. Tree nuts include pistachios, walnuts, cashews, and many other types of nuts. Though it is possible to be allergic only to cashews, most people with tree nut allergies are allergic to more than one type of tree nut, and it is safest to avoid all nuts because of the possibility of cross-contamination.
Cashew allergies result from an immune system response to the protein contained in cashews. Because the protein in cashews is similar to that found in pistachios, most people who are allergic to one are also allergic to the other. Cashew is found in many foods as a 'hidden ingredient,' including ice cream, cakes, granola bars, pesto sauce, and many Asian meals. If you are diagnosed with a cashew allergy, your doctor will recommend avoiding any food that may contain cashews in order to prevent an allergic reaction.
Peanut allergies may get a bad rap as far as food allergies go, but in fact many allergy suffers experience more severe reactions with a cashew allergy. The mildest allergic reactions to cashews include hives, swelling, and itching. Stomach cramps, nausea, and other gastrointestinal symptoms are also common. This allergy may also mimic the symptoms of asthma, particularly when the reaction is caused by inhaled cashew dust. This allergy often causes a severe reaction known as anaphylaxis, which includes a rapid heartbeat, throat swelling, difficulty breathing, lightheadedness, and loss of consciousness. This life-threatening reaction requires immediate treatment with epinephrine.