Antihistamines

Antihistamines are medications that counteract the effect of the natural chemical histamine. Histamine is a vasoactive chemical. This means it has an effect on small blood vessels, resulting in dilated capillaries (redness), and leakage of protein-rich fluid into surrounding skin (swelling). Histamine affects nearby nerves resulting in itching.

Antihistamines are often prescribed for itchy skin.