What is anaphylaxis?

Anaphylaxis is a potentially life-threatening reaction to an allergen. You are at risk for experiencing anaphylaxis if you have:

  • ever had an anaphylactic reaction
  • allergies or asthma
  • a family member who has experienced an anaphylactic reaction

Anaphylaxis happens fast and produces serious symptoms throughout the entire body. Without treatment, symptoms can cause serious health consequences and even death.

Becoming familiar with this information could help you recognize symptoms in time to save a life.

Anaphylaxis occurs when the body’s immune system overreacts to an allergen. Immune cells react to a harmless substance that has entered your body as if it were a threat.

Your immune cells trigger a reaction in order to destroy it.

Anaphylaxis may occur “out of the blue,” or after years of avoiding a known allergen. Some people experience exercise-induced anaphylaxis as well.

This is when the combination of exercise and exposure to an allergen creates anaphylaxis.

Those who have gone through anaphylaxis often describe an early “weird” feeling or “sense of impending doom.”

Since the reaction involves the whole body, people may get a sense that something is happening before any visible symptoms show up.

They may also feel anxious, like something is wrong, but they’re not quite sure what it is. A rapid heart rate may accompany this feeling, contributing to the overall sense of anxiety.

The first visible symptom of anaphylaxis usually appears on the skin, which gets red. Often, this occurs in the cheeks, and may look like flushing, though it will not include any sweating.

Redness can also occur on the chest and neck, or other areas of the body.

Next, the person may develop hives. Hives are itchy, raised welts on the surface of the skin.

The itching can be intense, but it’s important not to scratch to avoid wounds and potential scarring.

The affected area may also feel warm to the touch.

Next, swelling or inflammation will likely spread. Inflammation is a key sign of immune activity, and will often signal an allergic reaction.

The eyes, lips, hands, feet, and other areas of the face and body may swell up rapidly. Some people’s eyes swell shut, or their lips may increase in size.

Whenever body parts swell up, they may also itch and tingle. Itchy, swollen eyes, for instance, are common in an anaphylactic reaction.

While the body is swelling, other symptoms may occur, such as:

  • nasal congestion
  • sneezing
  • runny nose

The tongue may swell and the throat and chest may tighten up, which can cause the following symptoms:

  • coughing
  • trouble breathing
  • trouble swallowing
  • wheezing

These are some of the more dangerous symptoms that can lead to a lack of oxygen and other serious health consequences.

Anaphylaxis can also quickly affect the digestive system and cause symptoms that include:

  • cramps
  • nausea
  • diarrhea
  • vomiting

There may also be general abdominal pain, or even an urge to rush to the bathroom.

These symptoms are most common with food or medication allergies, and may last for hours after the initial reaction.

If you feel lightheaded, you could be experiencing a drop in blood pressure. This is related to your heart and blood vessel function during anaphylaxis.

The chemicals flooding your bloodstream may cause tiny blood vessels to widen, lowering blood pressure, and potentially causing dizziness.

Your heart rate may also change. It may speed up to try to compensate for the drop in blood pressure.

Those with existing heart disease are more at risk for cardiac symptoms from anaphylaxis, and may experience a heart “spasm.”

A heart spasm occurs when one of the arteries in the heart narrows. This narrowing can cause a lack of blood flow to the heart and result in chest pain.

Some people may even experience cardiac arrest, which is when the heart suddenly stops working.

As the release of histamine and other chemicals may affect the heart and chest, it can also cause changes in the brain.

People may experience headaches, confusion, and anxiety, and may have trouble speaking clearly.

Vision may be affected and become blurry. Some people may even faint or experience a loss of consciousness.

Seizures may also occur in rare cases.

Reviewing these symptoms can help you take immediate action when you observe them, either in yourself or someone else. If you see someone experiencing an anaphylactic reaction, call an ambulance. If the person has an epinephrine auto-injector, such as the EpiPen, use it.