Histamine has come into use as a test for circulatory function in the extremities and as a drug of more general usage. Since the work of Sollmann and Pilcher,1 Eppinger2 and Hess3 and under the influence of the experimental work of Lewis,4 the drug has taken its place in several fields of medical practice. Its use as a test of circulatory function and as a stimulant of gastric secretion is too well known to need description.
The cutaneous reaction to histamine is a triple response consisting of (1) a purple spot at the site of the puncture; this is usually obscured quickly by (2) the formation of a wheal, (3) the later appearance of an extended area of arterial dilatation—the flare. The ultimate picture closely resembles a mosquito bite—a wheal surrounded by a flare of redness averaging from one-half to 2 inches (1.3 to 5 cm.)