• Food

Peanuts, tree nuts (walnuts, cashews, etc.), shellfish, fish, milk, and eggs commonly cause anaphylactic reactions. Only a trace amount of a problem food can cause a reaction in some individuals.

In the United States, food-induced anaphylaxis is believed to cause about 30,000 trips to the emergency room and between 150 to 200 deaths each year. Individuals who are allergic to foods and have asthma are believed to be at a higher risk for developing an anaphylactic reaction.

A study of 32 cases of fatal food-allergy induced anaphylaxis showed that adolescents who have peanut and tree nut allergy and asthma, and who don’t have quick access to epinephrine during a reaction, are at highest risk for a fatal reaction.

Strict avoidance of the allergen is necessary for avoiding a severe reaction. Read food labels for every food each and every time you eat it. Ask questions about ingredients and preparation methods when eating away from home.

• Medication

Anaphylactic reactions to medication will typically occur within an hour after taking the drug; however, reactions may occur several hours later. It is estimated that up to 10 percent of the population may be at risk for allergic reactions to medications.

According to literature from The American Academy of Allergy, Asthma & Immunology, “The chances of developing an allergic reaction may be increased if the drug is given frequently, in large doses, or by injection rather than by pill. The most important factor may be an inherited genetic tendency of the immune system to develop allergies. Contrary to popular myth, however, a family history of allergy to a specific drug does not mean that a patient has an increased chance of reacting to the same drug.”

If you experience symptoms of an allergic reaction after taking medication, speak to your doctor. If symptoms are severe, or resemble anaphylaxis, get emergency medical help immediately.

For additional information about medication allergy, visit The American Academy of Allergy, Asthma & Immunology.

• Insect Sting

Honeybees, bumblebees, yellow jackets, hornets, wasps, fire ants, and harvester ants are the most common causes of insect stings in the United States.  The symptoms of anaphylactic reactions to insect stings usually occur within minutes of the sting.

Insect sting reactions can range from local to mild to life threatening. Local reactions can involve swelling of an area larger than the sting site (i.e., the entire arm can be swollen after a sting on the hand). This type of reaction may also include nausea and low-grade fever. Insect stings account for about 50 deaths each year.

To minimize the risk of an insect sting, avoid brightly colored clothing and/or scented cosmetics, perfumes, and so forth; avoid walking barefoot; use caution when cooking outdoors; and keep insecticide handy when working outdoors.

• Latex

Latex allergy is most commonly diagnosed in individuals who are exposed to latex frequently, such as those employed in the health care or rubber industry fields and children with spina bifida and other congenital diseases requiring multiple surgeries. An estimated 1% of the U.S. population has latex allergy. Approximately 10% to 17% of those employed in the health care occupations have this allergy.

Some individuals with latex allergy will also develop reactions when eating foods that cross-react with latex. These foods commonly include bananas, kiwi, avocados, and European chestnuts; and they less commonly include potatoes; tomatoes; and peaches, plums, cherries, and other pitted fruits.

For additional information about latex allergy, visit the American Academy of Allergy, Asthma & Immunology.

• Food-Dependent, Exercise-Induced Anaphylaxis

Food-dependent, exercise-induced anaphylaxis is very rare and occurs only when an individual eats a specific food and exercises within three to four hours after eating. Individuals experiencing this type of reaction typically have asthma and other allergic conditions. Although any food may contribute to this form of anaphylaxis, foods that have been reported include wheat, shellfish, fruit, milk, celery, and fish.

Food-dependent, exercise-induced anaphylaxis appears to be twice as common in females as it is in males and is common in individuals who are in their late teens to thirties.

• Idiopathic Anaphylaxis

Idiopathic anaphylaxis is a severe reaction in which no cause can be determined. It can affect individuals of all ages, although females are affected much more frequently than males. As with other forms of anaphylaxis, idiopathic anaphylaxis can be life threatening. Prophylactic daily treatment with a combination of medications can control the symptoms, and most episodes of idiopathic anaphylaxis subside spontaneously after several months or years.