Diseases & Conditions
A severe, life-threatening allergic reaction that occurs rarely in those who have an extreme sensitivity to a particular substance or allergen. The reaction, which often includes an itchy red rash or hives, is most common after an insect sting or as a reaction to a drug such as PENICILLIN. It also may occur as an allergic reaction to certain foods, such as tree nuts or peanuts. As the allergen enters the blood, it triggers the release of massive amounts of histamine and other chemicals that affect the body by expanding blood vessels and lowering blood pressure.
Anaphylaxis is a medical emergency. An injection of epinephrine (Epipen) can save the child’s life, but it must be given as soon as possible. A person who experiences anaphylaxis after a drug or a sting should lie down with legs raised, to improve blood ﬂow to the heart and brain.