Intracutaneous and skin prick testing with serotonin and histamine

Skin prick and intracutaneous tests were performed with serotonin, histamine and a mixture of both in 32 normal persons, two rhinitis patients and 12 asthmatics. Skin prick tests with serotonin produced a triple response, but the weal reactions were small. Serotonin had no potentiating effect on the histamine reaction. Intracutaneously, serotonin tests also induced a triple response, but with smaller weal reactions than with histamine, and the weal surfaces were wrinkled. Constriction of the large subcutaneous veins was observed locally after serotonin injection. No quantitative or qualitative difference in reaction to serotonin was observed between normal subjects and allergics. The role of serotonin in the immediate allergic reaction in the skin was minimal.