When the body’s immune system reacts abnormally to something a person eats or drinks, it’s known as a food allergy.
A food allergy may affect the skin, the gastrointestinal tract, or the respiratory or cardiovascular systems. Many types of foods can be allergens, but certain foods are much more likely than others to trigger an allergic reaction.
It is widely believed that eight foods are responsible for 90 percent of food allergies. They are:
• Cow’s milk
• Tree nuts (such as cashews or walnuts)
Symptoms of food allergies may range from mild to severe and they may come on suddenly or develop over several hours.
Because a person’s immune system may react to a very small amount of the allergen, food allergies are particularly dangerous and potentially life threatening, especially if breathing is affected. Because of this, people with asthma are at an increased risk for a fatal allergic reaction to food.
Mild symptoms related to a food allergy may include:
• Stuffy or runny nose
• Itchy, watery eyes
• Stomach cramps
Severe symptoms of an allergic reaction to food are:
• Difficulty breathing, including wheezing
• Swelling of the lips, tongue or throat
• Hives (an itchy, blotchy and raised rash)
• Dizziness or faintness
• Nausea or vomiting
Source – http://www.healthline.com