Exposure to tree nuts can trigger a multitude of symptoms in sensitive individuals. Symptoms typically appear within minutes of eating a tree nut or tree nut product, although some reactions are known to occur up to four hours after consumption and could reoccur hours later with a second wave of symptoms following the initial attack. Symptoms of an allergic reaction to tree nuts may include:

• Tingling feeling in the lips and mouth
  
  
• Itchy hives (urticaria), primarily when nuts make skin contact
  
  
• Swelling (angioedema), primarily when nuts make skin contact
  
  
• Vomiting or diarrhea
  
  
• Cramping stomach pains
  
  
• Dizziness, faintness or unconsciousness
  
  
• Shortness of breath
  
  
• Swelling in the throat (causing swallowing or breathing difficulties)

Allergic reactions to tree nuts can range from mild anaphylaxis (generalized allergic reaction involving two or more body systems) to severe and potentially life-threatening anaphylactic shock. There is no way to predict the severity of reaction when a person with food allergies ingests the problem foods. Therefore even people experiencing mild symptoms should immediately contact a physician or seek medical treatment. Some highly sensitive individuals will react to just a small portion of tree nuts with anaphylactic shock. This life-threatening condition is characterized by constriction of the air passageways and a dangerous drop in blood pressure.