Normal nasal cytology in infancy.

Nasal cytology in the first year of life has rarely been utilized diagnostically because of an early report that nasal eosinophilia is a common finding in normal young infants. Using an improved sampling technique with a flexible nasal probe, we obtained nasal mucosal specimens for histologic examination from 22 healthy infants and five infants with upper respiratory tract infections. None of the healthy infants had nasal eosinophilia and no adverse effects were noted during the sampling procedure. We concluded that the present sampling technique is as safe and effective in infants as in children and adults and that the majority of healthy young infants do not have nasal eosinophilia.