While most allergies are not serious and can be controlled with standard medication, some allergy attacks can lead to life-threatening complications. One of these life-threatening complications is called anaphylaxis.

Anaphylaxis is a severe, whole-body reaction. A severe allergy attack may be initiated by food, such as milk, wheat, eggs, or nuts. It can also be related to insect stings, such as those from wasps or bees, or some medication. Immediate medical attention is required to prevent the reaction from getting worse.

Learn more: Anaphylaxis »

The onset of anaphylaxis is relatively quick. You may experience a reaction within mere seconds of exposure to a substance that you’re allergic to. At this point, your blood pressure will decrease rapidly and your airways will constrict.

Symptoms of anaphylaxis include:

Many people who are aware of their severe allergies carry a medication called epinephrine, or adrenaline. This is injected into the muscle through an “auto-injector” and is easy to use. It acts quickly on the body to raise your blood pressure, stimulate your heart, decrease swelling, and improve breathing.

Anaphylaxis is caused by allergies, but not everyone with allergies has this severe reaction. Many people have experienced symptoms of an allergy, which may include:

An allergy occurs when your immune system overreacts to a specific substance (allergen). Allergens can include:

Read more: Allergies »

In children, the most common cause of anaphylaxis is food allergies. Common food allergies include those to milk, nuts, eggs, and seafood. Children are especially vulnerable to food allergies when they’re away from home. It’s important that you let all caregivers know about your child’s food allergies. Also, teach your child to never accept homemade baked goods or any other foods that might contain unknown ingredients.

In adults, the most common causes of anaphylaxis are medications and venom from insect bites. You may be at risk for anaphylaxis if you’re allergic to any medications, such as aspirin (Bayer), antibiotics, and penicillin.

When you come into contact with an allergen, your body assumes it’s a foreign invader and the immune system releases substances to fight it off. These substances result in other cells releasing chemicals, which causes an allergic reaction.

Anaphylaxis is a broad term for this allergic reaction. In fact, it can be broken down into subtypes. The different classifications are based on how quickly symptoms and reactions occur.

They include:

  • Uniphasic reaction: This is the most common type of anaphylaxis. The onset of the reaction is rather quick, with symptoms peaking about 30 minutes after exposure to an allergen. According to UpToDate, up to 90 percent of all cases end up being uniphasic reactions.
  • Biphasic reaction: Symptoms can occur up to 12 hours after your first reaction occurs.
  • Protracted reaction: This is the longest type of reaction. Symptoms can occur several hours (or even days) after your first reaction.

If you’re experiencing anaphylaxis, administer an epinephrine shot right away. Inject yourself in the thigh for the best results. You’ll then need to proceed to the emergency room as a follow-up. At the hospital, you may be given oxygen, emergency antihistamines, and intravenous cortisone.

If you think someone else is experiencing anaphylaxis, take these immediate steps:

  • Ask someone to call for medical help, or call 911 if you’re alone.
  • Ask the person whether they carry an epinephrine auto-injector, and if so, assist them according to label directions.
  • Help the person to remain calm and lie quietly with their legs elevated. If vomiting occurs, turn them onto their side to prevent choking. Don’t give them anything to drink.
  • If the person becomes unconscious and stops breathing, begin CPR, and continue until medical help arrives.

Learn more: How to perform cardiopulmonary resuscitation (CPR) »

It’s important to get medical treatment for an allergy attack, even if the person begins to recover. In many instances, symptoms can improve but then worsen quickly after a period of time. Medical care is necessary to prevent recurrence of the attack.

When left untreated, anaphylaxis can lead to anaphylactic shock, a dangerous condition where your blood pressure drops suddenly and your airways constrict. Your heart can also stop during shock.

In the most severe cases, anaphylaxis can cause death. Prompt treatment can prevent the life-threatening effects of anaphylaxis.

The outlook for anaphylaxis is positive when treatment measures are taken. Timing here is the key; anaphylaxis may prove fatal if it’s left untreated.

If you have severe allergies, you should always keep an epinephrine auto-injector on hand in case of anaphylaxis. Regular management with the help of an allergist can also help. Avoid known allergens whenever possible, and follow up with your doctor if you suspect any sensitivity to other undiagnosed allergens.