What is the primary action of antihistamines in allergic conditions?

The primary action of antihistamines in allergic conditions is to block the effects of histamine. Histamine is a chemical released by the body during an allergic reaction, leading to symptoms such as itching, swelling, and mucus production. Antihistamines work by binding to histamine receptors, specifically H1 receptors, thereby preventing histamine from exerting its effects on target tissues. This blockade helps alleviate various allergic symptoms, making antihistamines a key treatment option for conditions like allergic rhinitis, urticaria, and conjunctivitis. By counteracting the action of histamine rather than affecting its production or release, antihistamines effectively manage the discomfort associated with allergies.