Antihistamines are a class of medications that are commonly used to treat allergic reactions and allergic symptoms.
Antihistamine work by blocking the effects of histamine, a natural substance in the body that is released during allergic reactions, that causes symptoms such as itching, sneezing, runny nose, and swelling.
There are four main types of histamine receptors (H1, H2, H3, and H4), but antihistamines primarily target the H1 receptors. H1 receptors are located on various cells, including those in the respiratory and immune systems.
Common uses:
Allergic Rhinitis: Antihistamines are often used to relieve symptoms of seasonal and perennial allergies, commonly known as hay fever or allergic rhinitis.
Allergic Conjunctivitis: They can help alleviate itching and redness of the eyes associated with allergies.
Urticaria (Hives): Antihistamines are effective in reducing the itching and swelling of hives.
Itching: They can be used to relieve itching associated with various allergic skin conditions, insect bites, and contact dermatitis.