Food Allergies and Anaphylaxis: What You Need to Know
The greatest danger in food allergy symptoms comes from anaphylaxis, a violent allergic reaction involving a number of parts of the body simultaneously. Like the less serious food allergy symptoms, anaphylaxis usually occurs after a person is exposed to an allergen to which he or she was sensitized by previous exposure. In other words, it does not usually occur the first time a person eats a particular food.
Although any food can trigger anaphylaxis (also known as anaphylactic shock), peanuts, tree nuts, shellfish, milk, eggs, and fish are the most common culprits. As little as one fifth to one five-thousandth of a teaspoon of the offending food has caused death in people with food allergies.
Anaphylaxis can produce severe symptoms in as little as 5 to 15 minutes, although life-threatening reactions may progress over hours.
Signs of an anaphylactic reaction include:
- Difficulty breathing
- Feeling of impending doom
- Swelling of the mouth and throat
- A drop in blood pressure
- Loss of consciousness.
The sooner the anaphylaxis is treated, the greater the person's chance of surviving. The person should be taken to a hospital emergency room, even if symptoms seem to subside on their own.
There is no specific test to predict the likelihood of anaphylaxis, although allergy testing may help determine what a person may be allergic to and provide some guidance as to the severity of the allergy. Experts advise people who are at risk of anaphylaxis to carry medication, such as injectable epinephrine, with them at all times, and to check the medicine's expiration date regularly. Doctors can instruct patients with allergies on how to self-administer epinephrine. Such prompt treatment can be crucial to survival.
Injectable epinephrine is a synthetic version of a naturally occurring hormone known as adrenaline. For treatment of an anaphylactic reaction, it is injected directly into a thigh muscle or vein. Epinephrine works directly on the cardiovascular and respiratory systems by:
- Causing rapid constriction of blood vessels
- Reversing throat swelling
- Relaxing lung muscles to improve breathing
- Stimulating the heartbeat.