Exhaled nitric oxide is reduced in infants with rhinorrhea.

In infants, the effect of colds and other respiratory tract infections (RTI) on exhaled nitric oxide (FE(NO)) is not clear. In this study, we measured FE(NO) in 24 infants (14 boys) who presented with rhinorrhea, with or without cough but not wheeze. Twelve of these infants had a history of recurrent wheeze. Levels were compared with a group of 23 healthy infants (13 boys). Further, 8 infants (5 with a history of recurrent wheeze) with rhinorrhea were tested after symptoms had resolved. Infants with rhinorrhea had significantly lower FE(NO) than the healthy infants (11.9 vs. 23.8 ppb, respectively, P < 0.0007). Levels increased from 7.5 ppb to 34.1 ppb in the 8 infants tested with and without symptoms (P = 0.0002). Infants with rhinorrhea have reduced FE(NO), irrespective of their respiratory history.