What is it?

Anaphylactic reaction, or Anaphylaxis, is a medical emergency, caused by a strong allergic reaction.
The reaction causes the immune system to release chemicals into the blood that can cause shock, including a sudden drop in blood pressure, narrowing and blocking the airways.
Anaphylaxis starts in minutes to hours, and increases very rapidly to life-threatening levels, therefore diagnosing and treatment is important.

The reaction is an inflammatory and immunological response triggered by almost any foreign substance, including food, medication and insects bites, while nuts and seeds are the most common foods. It can lead to severe anaphylactic reaction, and even death.
Anaphylaxis and allergic reactions are more common in people with asthma, eczema, or allergic rhinitis.