What are food allergies?

To understand why food allergies are a serious problem, it's worth knowing a little about why they happen.

Allergies occur when the immune system mistakenly perceives a harmless substance as a threat. Immune cells begin to mount a defense, triggering inflammation and other reactions. The immune reaction causes the familiar symptoms of allergies, including redness, itching and swelling.

Most of us are familiar with pollen allergies, which occur when the body responds to pollen, causing itchy nose and watery eyes. Food allergies are very similar, except that the offending substance is a particular food, such as eggs or shellfish.

In mild cases, a food allergy may cause only itching and redness around the lips and mouth. In more serious cases, a runaway allergic reaction can cause anaphylaxis. An anaphylactic reaction may begin with a tingling sensation or itching sensation on the lips and in the mouth. It can progress to wheezing or other difficulty breathing, coughing, swelling of the mouth and throat, vomiting, diarrhea, cramping, a drop in blood pressure, and loss of consciousness. Without immediate treatment, anaphylactic reactions can be fatal. Injectable epinephrine or antihistamines can halt the symptoms of anaphylaxis. It is essential that anyone with symptoms of possible anaphylaxis get emergency treatment immediately.

Again, such severe reactions are rare. But preventing even mild adverse reactions is important.

Common Sites for Food Allergies

• Mouth (swelling, itching)
• Airways (wheezing or breathing problems)
• Digestion tract (cramps, vomiting, diarrhea)
• Skin (hives, rashes or eczema)
• Anaphylaxis (a life threatening reaction that involves many parts of the body)