Overview

Sneezing, itchiness, foggy brain: These are all symptoms you might experience from time to time if you have allergies.

But anaphylaxis is a type of allergic reaction that’s much more serious. During anaphylactic shock, your body goes into overdrive by producing inflammatory chemicals to attack the allergen. In turn, this acute response affects other parts of your body, too.

Learn more about the symptoms that occur during anaphylaxis as well as the overall effects on your body.

Anaphylaxis isn’t the same as allergies, though this is how the severe reaction starts. You may have a food intolerance or a minor allergic reaction to something you encounter, but this isn’t anaphylaxis.

Almost any substance can be an allergen, including foods and insect bites or stings. The cause can’t always be pinpointed. The first time you’re exposed to the substance, your immune system learns to recognize the foreign invader.

But with anaphylaxis, your immune system has an exaggerated response when you’re exposed to the substance again. This response affects the whole body and may put your life in danger. Symptoms may begin within seconds. They can progress swiftly as well.

The first line of treatment is usually adrenaline (epinephrine shots), because it can turn things around quickly. Once you’ve experienced anaphylaxis, you’re always at risk, so you should try to avoid potential allergens as much as possible.

Your doctor will likely prescribe adrenaline in the form of a prefilled autoinjector that you can carry with you. If you need to use the autoinjector pen, you can inject yourself or have someone else do it for you.

You should always seek medical help after using adrenaline. Symptoms sometimes return hours or even days after receiving epinephrine treatment.

Immune system

Your immune system fights antigens like bacteria, viruses, and fungi. It learns to recognize these harmful substances and works to neutralize them. Once your immune system interacts with an antigen, it stores the information for future use. When it’s doing its job, you don’t get sick.

Sometimes, when your body encounters that antigen again, your immune system overreacts. Far too much histamine and other inflammatory chemicals are quickly released into your system. This leads to a wide variety of symptoms throughout the body. It can quickly turn into a medical emergency.

Adrenaline is a hormone produced naturally by your body. In anaphylaxis, an extra dose can help increase blood flow throughout your body and help reverse the immune system’s aggressive response. This is why your doctor will recommend adrenaline (epinephrine) injections in the case of anaphylaxis. It will stop the inflammation from spreading to other body systems.

Respiratory system

Once inflammation affects your respiratory system, your bronchial tissues may start to swell. Symptoms include shortness of breath and difficulty breathing. It can also cause fluid in the lungs (pulmonary edema) and cough. You may make high-pitched or wheezing sounds when you breathe. A tightening, painful sensation in the chest is common. 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. You’re at an increased risk if you have asthma.

Skin (integumentary system)

One of the more obvious signs of anaphylaxis can be seen on the skin. However, skin symptoms don’t occur in every anaphylactic shock. While they’re certainly possible, anaphylaxis can still occur without skin symptoms.

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. Pale skin means you’re going into shock.

Circulatory system

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.

When major organs don’t get the blood and oxygen they need to function, your body goes into anaphylactic shock. This is a life-threatening medical emergency. When left untreated, anaphylactic shock can lead to internal organ damage, or even cardiac arrest.

Digestive system

Digestive symptoms are also possible, especially if you have food allergies. These can occur with or without other symptoms of anaphylaxis. Digestive symptoms include:

  • bloating
  • cramps
  • abdominal pain
  • nausea
  • vomiting
  • diarrhea

Central nervous system

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:

  • a metallic taste in your mouth
  • dizziness or lightheadedness
  • headache
  • swelling of the eyes, lips, and tongue
  • throat swelling, which may block your airways
  • confusion, anxiety, and weakness
  • slurred speech, hoarse voice, and difficulty talking

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.