An allergy is an adverse reaction by the body to a foreign material. Reactions range from mild to severe.

A mild reaction affects only a specific area of the body and causes rashes, itchiness, watery eyes or congestion.

A severe reaction is a rare and life-threatening reaction called anaphylaxis and requires immediate medical attention.

A severe reaction affects the whole body and causes generalized itchiness, difficulty breathing, sudden swelling and loss of consciousness.