How long the effects of anaphylaxis last depends on how quickly you get treatment. The symptoms may last from a few minutes to several hours. Without immediate medical treatment, the result can be death, but early treatment can help prevent serious complications.

Do not delay seeking help.

If you have had a previous severe allergic reaction:

• Tell your doctor about all past allergic reactions you have had.
• Avoid foods, chemicals, and other substances that have caused allergic reactions. For example, if shrimp causes an allergic reaction, don't eat shrimp or any food that might contain shrimp. If you have drug or food allergies, always check labels before taking medicines or eating foods. This includes nonprescription medicines.
• Ask your doctor to prescribe medicine kits for treating anaphylaxis. Make sure you review the instructions with your doctor. Check the expiration dates. Carry one kit with you in your briefcase, sports bag, or handbag, and keep one at home. Do not keep kits in the car. The medicines will not work well if they get too hot or cold.
• Be prepared to give yourself a shot in case of an emergency. Think of the shot as something you can do to keep yourself alive long enough to get medical attention.
• Wear a bracelet or necklace that warns of your allergy and tells what to do in case of an emergency. Tell your family, friends, and co-workers what they should do if you have a severe allergic reaction.
• Consider having immunotherapy, in which your immune system is gradually exposed to the toxic substance to make it less harmful to you. Immunotherapy is very effective for insect allergies but not for food allergies.
• Tell all pharmacists, doctors, and dentists who treat you about any allergies you have. Some medicines contain ingredients that may cause an allergic reaction for you.
• For more information, contact: The Food Allergy & Anaphylaxis Network (FAAN)
• Phone: (800) 929-4040
• Web site: http://www.foodallergy.org .

Learn what substance causes your reaction and avoid that substance. Ask your doctor if desensitization treatments, such as allergy shots, might help you.