Anaphylaxis is primarily an allergic reaction. Allergic reactions become anaphylaxis once an allergy begins to affect more than one body system, such as the skin and respiratory system. Anaphylaxis comes on suddenly and the symptoms progress quickly. It will develop most commonly after eating, getting stung by an insect, or taking medications.
Symptoms can be seen in many parts of the body:1
- Skin: You may have flushing and itching. Hives can develop, which are raised itchy bumps that blanch (turn white) when you press on them. Angioedema can develop, which is swelling under the skin.
- Eyes: You may have signs of irritation including itching, redness, production of tears, and the skin may swell around the eyes.
- Upper respiratory: Congestion, a runny nose, and sneezing can develop. You can feel throat swelling, choking, or hoarseness.
- Oral: You may experience a swollen tongue, lips, or throat, or abnormal taste sensations.
- Lower respiratory: You can have difficulty breathing, wheezing, and chest tightness
- Circulatory: You may have a rapid or slow heartbeat and low blood pressure. You may feel dizzy, faint, or you may pass out.
- Nervous system: You can become anxious or confused, have slurred speech, and may even feel a sense of impending doom.
- Digestive system: Nausea, vomiting, diarrhea, or abdominal pain may be experienced.
Anaphylaxis becomes anaphylactic shock when a person shows signs of low blood pressure:
- Pale color
Anaphylactic shock often includes shortness of breath. A person doesn’t always have trouble breathing, but if the symptom is present, it’s a good indicator that the allergic reaction is turning into anaphylaxis.
Allergen Exposure as a Sign
It’s easier to identify the signs and symptoms of anaphylactic shock if there is a known allergen exposure. For instance, those with allergies to bee stings will usually know they’ve been stung. Anyone who’s had allergic reactions in the past should be aware of any symptoms, even if no allergen exposure has been identified. For example, people with food allergies are more likely to have anaphylaxis while eating even when they don’t think they’re eating the food they are allergic to.