inflammation, but not other patterns of inflammation, is closely associated with favourable
short-and long-term responses to corticosteroid therapy, irrespective of the clinical context in
which it occurs. Moreover, a raised exhaled nitric oxide (FENO) is a reasonable marker of
eosinophilic airway inflammation, which has a number of advantages as a diagnostic and
monitoring tool. In this review we outline essential background information on the use of …