Anaphylaxis is a potentially life-threatening allergic reaction. Symptoms may include hives, swelling of the face, neck or throat, asthma (wheezing, difficulty breathing), lightheadedness or fainting secondary to low blood pressure, or gastrointestinal symptoms such as nausea, vomiting, abdominal cramps or diarrhea. Anaphylaxis may be caused by a specific allergic trigger such as a food, insect sting, natural rubber latex or medication. It may also be induced by nonspecific factors such as exercise, temperature extremes or even viral infections. The treatment for acute anaphylaxis is epinephrine which is a naturally occurring hormone. Other medications including antihistamines and steroids are frequently prescribed. Most patients with a history of anaphylaxis will be given an self-injecting form of epinephrine. There is a tendency on the part of patients and some doctors to delay epinephrine use until the more severe symptoms of anaphylaxis develop. However, it’s important to note that a delay in use of epinephrine is linked to fatal food anaphylaxis. The other risk factor for fatal food reactions is poorly controlled asthma, a point I always make to asthmatic patients with food allergy. Most important: Don’t Fear Epinephrine!!
IMPORTANT NOTE: If dizzy or lightheaded, lie the patient down, legs elevated to maintain consciousness. Do not sit the patient up (even after epinephrine injection). Wait for an ambulance.
Courtesy of the Mayo Clinic:
Whether or not you know what caused your life-threatening allergy attack you should see an allergist. Specific tests for foods and tests for markers of overactive allergic cells can be performed. Depending on the nature of the problem, prophylactic daily medications may be prescribed to prevent or reduce the severity of subsequent reactions. The same medications used for treatment can be effective including antihistamines. Rarely, more serious conditions of the allergic cells (mast cells) may be the cause of anaphylaxis and it is critical to identify these patients. Your allergist can test for these conditions (usually blood testing).