Anaphylaxis is a medical emergency. Though rare, this serious type of allergic reaction occurs after a person is exposed to an allergen (a substance they are allergic to), such as certain foods, medications, or insect stings.
The body's immune system quickly reacts, causing swelling of the face and throat, difficulty breathing, dangerously low blood pressure, and leaky blood vessels. These effects can lead to shock. If not treated quickly, anaphylaxis can be fatal.
Avoiding the allergen and knowing what to do if you are exposed are the keys to managing the problem.