histamine headache, a headache associated with the release of histamine from the body tissues and marked by symptoms of dilated carotid arteries, fluid accumulation under the eyes, tearing or lacrimation, and rhinorrhea (runny nose). Symptoms include sudden sharp pain on one side of the head, involving the facial area from the neck to the temple. Treatment includes the use of preparations of antihistamines and ergot that help constrict the arteries. Also called cluster headache, Horton’s histamine cephalalgia. See also cephalalgia.