Plasma histamine levels during the first week of life.

Babies asphyxiated at birth and premature babies who develop the idiopathic respiratory distress syndrome of the newborn excrete larger than normal quantities of histamine in the urine during the first 24 hours of life (Cooper and Davis, 1968). Since histamine could play a part in the genesis of the respiratory distress syndrome it seemed important to establish normal plasma levels for the newborn. There is considerable evidence to support the view that histamine in the blood is carried in the eosinophil and basophil leucocytes (Graham et al., 1955; Mitchell and Cass, 1959). If the action of the eosinophils is to counter that of histamine, as has been shown to be the case in race-horses (Archer, 1963), newborn babies with an 'eosinophil rash' (urticaria neonatorum, erythema toxicum neonatorum) might be expected to have some abnormality of histamine metabolism. Eosinophil rash is a transient exanthem commonly seen during the first 4 days of life, which usually passes through stages of erythema, papules, and finally pustules; the latter contain large numbers of eosinophils. There is no evidence that it is infective in origin (Finlay and Bound, 1953). We have, therefore, studied plasma histamine levels in a group of infants with severe pustular eosinophil rashes, and compared them with those in normal unaffected infants.