Blood histamine levels (BHL) in infants and children with respiratory and non-respiratory diseases.

BACKGROUND Blood histamine levels are decreased after severe allergic reactions and in various chronic diseases. AIMS To study blood histamine levels in infants and children with acute infectious and non-infectious, non-allergic, disease. METHODS Blood histamine levels were investigated by a fluorometric method in infants and children admitted to hospital with bronchiolitis, non-wheezing bronchitis, acute infections of the urinary tract, skin and ear-nose-throat, gastroenteritis, or hyperthermia of unknown aetiology. Results of blood histamine levels and white blood cell counts were compared with those obtained for children recovering from benign non-infectious, non-allergic illnesses. RESULTS As compared with control children, white blood cell numbers were significantly increased in children with acute infections of the urinary tract, skin and ear-nose-throat, and were significantly decreased in children with gastroenteritis. Blood histamine levels were significantly lower in children with gastroenteritis and hyperthermia than in children with other diseases and control children. It was not possible to correlate blood histamine levels and the number of blood basophils. CONCLUSIONS BHL are significantly decreased in infants and children with acute gastroenteritis and hyperthermia of unknown aetiology. The mechanisms responsible for the decrease in blood histamine levels in children with gastroenteritis and hyperthermia are discussed.