Mycoplasma pneumoniae - Associated bronchiolitis causing severe restrictive lung disease in adults - Report of three cases and literature review

Study objectives: To characterize adult Mycoplasma pneumoniae-induced bronc hiolitis requiring hospitalization, Design: We encountered an adult patient with severe bronchiolitis in the ab sence of pneumonia due to M pneumoniae, To determine the relative frequency of such a condition, we retrospectively reviewed the medical records of ad ults over a 4-year period with a hospital discharge diagnosis of "bronchiol itis" from a university hospital. Setting: University Hospital of the University of Colorado Health Sciences Center, Denver, CO. Study subjects: From 1994 to 1998, 10 adult inpatients were identified with a diagnosis of bronchiolitis, There were two with respiratory bronchioliti s, one with panbronchiolitis, one patient with bronchiolitis obliterans org anizing pneumonia (BOOP), and six with acute inflammatory bronchiolitis. In cluding the initial patient, three had a definitive clinical diagnosis of M ycoplasma-associated bronchiolitis, Results: The three adult patients with bronchiolitis due to M pneumoniae ar e 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 br onchiolitis 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 wit h inflammatory bronchiolitis had an unusual pattern of marked ventilation a nd perfusion defects localized predominantly to the left lung. All three ha d restrictive ventilatory impairment on physiologic testing. Conclusions: In adults, Mycoplasma-associated bronchiolitis without pneumon ia is rarely reported, but in hospitalized patients, it may be more common than expected and may be associated with severe physiologic disturbances.