• Be aware of the symptoms of a walnut allergy.big and small walnuts on walnut leaves image by Maria Brzostowska from Fotolia.com
  
  A walnut, or tree nut, allergy occurs when the body produces histamines in response to a protein in the nut. The protein may be present in the nuts themselves or in a nut product, such as oils. People with walnut allergies may also be allergic to other tree nuts, like cashews, hazelnuts and pecans. They may also be allergic to peanuts, which are not tree nuts but have similar proteins. Symptoms of a tree nut allergy vary from mild to life-threatening depending on the individual and can affect the whole body.
  
  

Skin Signs and Symptoms

• According to Kidshealth.org, skin reactions are the most common symptoms of food allergies. Patients may experience mild itching and swelling around the mouth. There may also be itching on the tongue, gums and throat. The area around the eyes may itch and swell, and the eyes may become watery and irritated. There may also be hives, eczema and swelling in other parts of the body.
  
  

Respiratory Signs and Symptoms

• Patients with a walnut allergy may experience sneezing, coughing, and wheezing as a result of the swelling caused by the histamines. There may also be chest and sinus congestion as well as a runny nose. In those with asthma, an allergic reaction to nuts may trigger an asthma attack.
  
  

Gastrointestinal Signs and Symptoms

• Those with a walnut allergy may experience mild stomach and intestinal cramping, gas and bloating. There may also be diarrhea and vomiting. It's easy to confuse an allergic reaction with food poisoning. Generally, with an allergy, the patient will exhibit gastrointestinal symptoms along with skin and/or respiratory symptoms.
  
  

Life-threatening Signs and Symptoms

• In severe cases of walnut allergy, the patient's throat, tongue and structures in the lungs may swell so much that the patient can no longer breathe. This life-threatening condition, called anaphylaxis, requires immediate medical attention. Anaphylaxis strikes suddenly and may occur in conjunction with some of the other symptoms.
  
  

Misleading Signs and Symptoms

• Some people might have very mild reactions to walnuts and continue to eat them because they don't find the symptoms bothersome. However, as with any allergy, it is possible for someone to have a very mild reaction over several exposures and then suddenly have a more severe, even life-threatening, response. Additionally, it is possible for someone to develop an allergy at any time, not just in childhood. Anyone who suspects a walnut allergy should avoid eating walnuts and other tree nuts, and consult an allergist for testing.