First aid - Anaphylaxis

A severe allergic reaction (anaphylaxis) can produce shock and life-threatening respiratory distress and circulatory collapse.

In sensitive people, anaphylaxis can occur within minutes, but may also occur up to several hours after exposure to a specific allergy-causing substance. A wide range of substances — including insect venom, pollen, latex, and certain foods and drugs — can cause anaphylaxis. Some people have anaphylactic reactions from unknown causes.

If you're extremely sensitive, you might break out in hives and your eyes or lips might swell severely. The inside of your throat might swell as well, even to the point of causing difficulty breathing and shock. Your blood pressure drops, and your internal organs can be affected. Dizziness, mental confusion, abdominal cramping, nausea, vomiting or diarrhea also may accompany anaphylaxis.

How you can be ready:

If you've had an anaphylactic reaction in the past, carry medications with you as an antidote. Epinephrine is the most commonly used drug for severe allergic reactions. It comes only as an injection that must be prescribed by your doctor. You can self-administer epinephrine with an auto-injector, such as the EpiPen. Be sure to read the injection instructions as soon as you receive an auto-injector, and have your household members read them as well.

You should also carry an antihistamine pill, such as diphenhydramine (Benadryl, others), because the effects of epinephrine are only temporary. Seek emergency medical attention immediately after taking these medications.

If you observe someone having an allergic reaction with signs of anaphylaxis:

1. Call your local medical emergency number.
2. Check for special medications that the person might be carrying to treat an allergic attack, such as an auto-injector of epinephrine (for example, EpiPen). Administer the drug as directed — usually by pressing the auto-injector against the person's thigh and holding it in place for several seconds. Massage the injection site for 10 seconds to enhance absorption. After administering epinephrine, have the person take an antihistamine pill if he or she is able to do so without choking. Look for a medical emergency ID bracelet or necklace.
3. Have the person lie still on his or her back with feet higher than the head.
4. Loosen tight clothing and cover the person with a blanket. Don't give anything else to drink.
5. If there's vomiting or bleeding from the mouth, turn the person on his or her side to prevent choking.
6. If there are no signs of circulation (breathing, coughing or movement), begin CPR.