Home > Encyclopedia of Children's Health > Antihistamines

Definition

Antihistamines are drugs used to treat the symptoms of allergies and allergic rhinitis by blocking the action of histamine, a chemical released by the immune system in allergic reactions.

Description

Antihistamines are used to treat the sneezing, runny nose, and itchy eyes of allergies and allergic rhinitis, as well as allergic skin reactions and anaphylactic reactions to insect stings and certain foods. Antihistamines are available as prescription and over-the-counter tablets, topical preparations, nasal sprays, and eye drops.

Antihistamines work by blocking the effects of histamine, a chemical released by mast...