Histamine and the skin.

The role of histamine in urticaria is reviewed with particular reference to experiments on cold contact urticaria. In this model, histamine release clearly has a central role, but the failure of drugs which suppress histamine release to alleviate symptoms, other than itching, suggests that other pharmacological agents must be involved. Evidence is presented that prostaglandin E may play a role in some of these patients. The discovery that human blood vessels possess H2 receptors as well as H1 receptors is discussed with particular reference to the role of combined H1 and H2 pharmacological blockade.