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

BACKGROUND: Blood histamine levels are decreased after severe allergic reac tions and in various chronic diseases. Aims: To study blood histamine levels in infants and children with acute in fectious 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-wheezi ng bronchitis, acute infections of the urinary tract, skin and ear-nose-thr oat, gastroenteritis, or hyperthermia of unknown aetiology. Results of bloo d histamine levels and white blood cell counts were compared with those obt ained for children recovering from benign non-infectious, non-allergic illn esses. Results: As compared with control children, white blood cell numbers were s ignificantly increased in children with acute infections of the urinary tra ct, skin and ear-nose-throat, and were significantly decreased in children with gastroenteritis. Blood histamine levels were significantly lower in ch ildren with gastroenteritis and hyperthermia than in children with other di seases and control children. It was not possible to correlate blood histami ne levels and the number of blood basophils. Conclusions: BHL are significantly decreased in infants and children with a cute gastroenteritis and hyperthermia of unknown aetiology. The mechanisms responsible for the decrease in blood histamine levels in children with gas troenteritis and hyperthermia are discussed.