What is a severe allergic reaction known as?

A severe allergic reaction is known as anaphylactic shock. This condition occurs when the immune system overreacts to a substance (allergen) it mistakenly identifies as harmful. Anaphylaxis can trigger a rapid, widespread release of chemicals in the body, leading to symptoms that may include difficulty breathing, swelling of the throat, hives, and a drastic drop in blood pressure. This reaction can be life-threatening and requires immediate medical attention, often treated with epinephrine to reverse the effects.

In contrast, the other options do not accurately describe a severe allergic reaction. A hypotensive response refers to a drop in blood pressure and could be a symptom of anaphylaxis, but it does not encompass the full spectrum of anaphylactic reaction. A simple allergy typically refers to less severe allergic reactions that might cause localized symptoms, such as sneezing or mild skin irritation, without systemic involvement. Severe intolerance is not a standard medical term related to allergic reactions; it generally suggests a strong adverse reaction to certain substances but lacks the life-threatening implications of anaphylaxis.