characterize adult Mycoplasma pneumoniae-induced
bronchiolitis requiring hospitalization.
encountered an adult patient with severe bronchiolitis in the absence
of pneumonia due to M pneumoniae. To determine the relative
frequency of such a condition, we retrospectively reviewed the medical
records of adults over a 4-year period with a hospital discharge
diagnosis of “bronchiolitis” from a university hospital.
Setting: University Hospital of the University of Colorado
Health Sciences Center, Denver, CO.
From 1994 to 1998, 10 adult inpatients were identified with a diagnosis
of bronchiolitis. There were two with respiratory bronchiolitis, one
with panbronchiolitis, one patient with bronchiolitis obliterans
organizing pneumonia (BOOP), and six with acute inflammatory
bronchiolitis. Including the initial patient, three had a definitive
clinical diagnosis of Mycoplasma-associated bronchiolitis.
Results: The three adult patients with bronchiolitis due to
M pneumoniae are unusual because they occurred in the
absence of radiographic features of a lobar or patchy alveolar
pneumonia. Hospital admission was occasioned by the severity of
symptoms and gas exchange abnormalities. One patient had bronchiolitis
as well as organizing pneumonia (BOOP) that responded favorably to
corticosteroid treatment. The other two had high-resolution CT findings
diagnostic of an acute inflammatory bronchiolitis. One of the patients
with inflammatory bronchiolitis had an unusual pattern of marked
ventilation and perfusion defects localized predominantly to the left
lung. All three had restrictive ventilatory impairment on physiologic
Conclusions: In adults, Mycoplasma-associated
bronchiolitis without pneumonia is rarely reported, but in hospitalized
patients, it may be more common than expected and may be associated
with severe physiologic disturbances.