Effects of corticosteroids on distribution of histamine in the blood of asthmatic children.

Blood and plasma histamine levels, together with circulating basophil and eosinophil counts, were estimated in a group of asthmatic children. Short-term studies were carried out on 7 patients, each of whom was given a single dose of corticosteroid, and the effects of the hormone were monitored for periods of up to two hours. Usually a fall occurred in the whole blood histamine level, basophil count, and eosinophil count, but no change occurred in the plasma histamine level, which remained very low throughout. In 3 cases, follow-up studies showed that in 2 cases out of 3, whole blood histamine levels were lower during treatment with corticosteroids, than when steroids were not being given.