Why does anaphylaxis cause difficulty breathing

Anaphylaxis happens when the body reacts to a foreign substance as if it were a serious threat to health. The most common triggers for these reactions are medications, foods, and insect stings. Some foods that often trigger allergic reactions include:. Any substance that causes an allergic reaction is called an allergen. For some people, even minimal exposure to traces of an allergen can cause a severe reaction. In its reaction to an allergen, the body produces large amounts of histamine — a signaling molecule that can trigger an inflammatory response.

In a person experiencing anaphylaxis, the airways often become narrow, making breathing difficult. In addition, the blood vessels may leak, causing edema , a type of swelling that results from the accumulation of fluid. The reaction may happen immediately after contact with the allergen or within hours of contact.

Very occasionally, it happens days later. The person may also have itchy, red, watery eyes, a headache , and cramping of the uterus. They may have a metallic taste in their mouth. Severe breathing difficulties, a significant drop in blood pressure, or both can lead to shock, which can be fatal.

If the person has a history of severe reactions, they may be carrying an adrenaline, or epinephrine, injection kit. It may contain an auto-injector, such as an EpiPen. If a child needs the medication, calm them first, and ensure that they are still. This will leave both hands free to operate the device. When using an EpiPen injector, it is essential to :. After the dose is administered, the orange end will cover the needle and the window of the device will be blocked.

If the needle tip is still visible, do not reuse the needle. Never flip off the blue safety release with a thumb — always use two hands to prepare the injector. Removing the safety release incorrectly can cause the injector to release its contents too early. As a result, there may be no medication in the device when the person administers it. There are different types of injector.

While they generally work in the same way, the instructions for each type may be slightly different. While waiting for help, ensure that the person can breathe. Eating certain foods before exercise or exercising when the weather is hot, cold or humid also have been linked to anaphylaxis in some people. Talk with your health care provider about precautions to take when exercising. If you don't know what triggers an allergy attack, certain tests can help identify the allergen.

In some cases, the cause of anaphylaxis is not identified idiopathic anaphylaxis. There aren't many known risk factors for anaphylaxis, but some things that might increase the risk include:.

The best way to prevent anaphylaxis is to stay away from substances that cause this severe reaction. If you have food allergies, carefully read the labels of all the foods you buy and eat.

Manufacturing processes can change, so it's important to periodically recheck the labels of foods you commonly eat. When eating out, ask how each dish is prepared, and find out what ingredients it contains.

Even small amounts of food you're allergic to can cause a serious reaction. Even if you're careful, at some point you'll likely be exposed to what you're allergic to.

Fortunately, you can respond quickly and effectively to an allergy emergency by knowing the signs and symptoms of an anaphylactic reaction and having a plan to quickly treat those symptoms. Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission. This content does not have an English version. This content does not have an Arabic version. Overview Anaphylaxis is a severe, potentially life-threatening allergic reaction.

Request an Appointment at Mayo Clinic. Share on: Facebook Twitter. Show references Campbell RL, et al. Your voice may go hoarse, and you may not be able to swallow. Respiratory distress is a life-threatening emergency. It requires immediate medical attention.

Untreated, it can lead to respiratory arrest. One of the more obvious signs of anaphylaxis can be seen on the skin. Anaphylactic skin symptoms may start out as itchiness, redness, or just a mild warming of the skin. It can progress to itchy hives that hurt when you touch them.

The actual color of your skin can change, too. Redness is common if you also have hives. If your respiratory system is in trouble, your skin may turn blue from lack of oxygen. During anaphylaxis, small blood vessels capillaries begin to leak blood into your tissues. This can cause a sudden and dramatic drop in blood pressure. Other symptoms include a rapid or weak pulse and heart palpitations. This is a life-threatening medical emergency. When left untreated, anaphylactic shock can lead to internal organ damage, or even cardiac arrest.

Digestive symptoms are also possible, especially if you have food allergies. These can occur with or without other symptoms of anaphylaxis. Digestive symptoms include:. Even before the first physical symptoms occur, you might experience a weird feeling, a sense that something bad is about to happen. This may accompany other symptoms, such as:.

As your body goes into shock, loss of consciousness occurs. This is why prompt treatment and medical attention are vital to preventing possible complications of anaphylaxis. Anaphylaxis is a life-threatening allergic reaction that causes a range of symptoms. Check out pictures of the symptoms, and learn more about them.

If you have an allergy to peanuts, you may be at risk for delayed anaphylaxis. Here are the symptoms to watch for and preventative measures to take.

Sallow skin refers to skin that has lost its natural complexion. Your skin may appear yellow or brown in tone, especially on your face.