Examination of nasal secretions
Cytological examination of nasal secretions was performed when children
had no signs of an acute respiratory infection. Nasal secretions were
sampled by swabbing the bilateral inferior turbinates with cotton swabs.
The samples were spread onto a slide glass, air-dried, fixed and stained
with Hansel solution (Eosinostein®; Torii
Pharmaceutical, Tokyo, Japan). The specimens were examined by light
microscopy for eosinophils, neutrophils and bacteria by a single
well-trained laboratory technician. Nasal eosinophilia was defined as
the presence of more than a few eosinophils in the whole field. The
percentage of eosinophils compared with neutrophils was also determined,
and >10% was defined as significant nasal
eosinophilia.17