Nuts, which are high in protein and considered to be "good" fats, can be a healthy food choice. But they can also have side effects, mostly in the form of allergic reactions. An allergy to peanuts is the third most common food allergy in young children, and the most common allergic reaction in older children and adults, according to the University of Chicago Pritzker School of Medicine. Nut allergies cause symptoms from the annoying to the life-threatening. Processed foods that contain nuts or that are manufactured in factories where cross-contamination might occur must label their products.
Skin Reactions
Skin reactions are the most common type of food allergy reactions, according to TeensHealth from Nemours. Typical skin reactions include rash, facial swelling -- especially around the eyes or mouth -- hives, itching, a tingling sensation in the mouth or general redness. Facial swelling, also called angioedema, is reported by 51 percent of people with peanut allergy, the University of Chicago reports; hives affect 47 percent. Some people develop canker sores, which are small, painful mouth ulcers, when they eat walnuts.
Respiratory Reactions
Typical allergy reactions that affect the respiratory tract include sneezing, runny nose or coughing. Respiratory allergic reaction to nuts can cause also life-threatening side effects. Swelling in the throat and airways can cause shortness of breath, a tight feeling in the throat or wheezing; these symptoms require immediate medical treatment. Throat tightness is the most common side effect in a peanut allergy, reported by 53 percent, according to the University of Chicago. Shortness of breath occurs in 41 percent and wheezing in 29 percent. Breathing in peanut dust or smelling peanuts usually isn't enough to set off an allergic reaction, Nemours states. In rare cases where lots of peanut shells are being cracked, such as at a restaurant or bar, especially if the space is small or enclosed, a reaction may occur.
Systemic Reactions
Around 75 percent of children with peanut allergies will develop a severe reaction on their first exposure, according to the University of Chicago, with the average age for a first allergic reaction to peanuts being 14 months. Anaphylaxis causes circulatory collapse, with low blood pressure, heart arrhythmias and loss of consciousness. Death can occur without prompt treatment. People with nut allergies should carry an epi-pen, which contains adrenaline, at all times. Administer at the first sign of significant reaction.
Gastrointestinal Reactions
Abdominal pain or cramping, diarrhea, nausea and vomiting can also occur as part of an allergic reaction to nuts. Vomiting affects 17 percent of people with a peanut allergy and diarrhea occurs in 6 percent, the University of Chicago states.
