In Reply.—Reflecting on the thoughtful comments of Henry and colleagues took me beyond the issue of "what's in" the diagnosis of bronchiolitis to the generic issue of the meaning of any diagnostic label. In unraveling clinical syndromes, the task of the clinician, epidemiologist, and pathologist is to identify illness episodes that may be clustered in useful categories. Each category is given a label and, thus, becomes a diagnosis. However, what purpose(s) should be served in this classification process? On what basis should we classify, ie, what should our criteria be? Answers to the former question shape answers to the latter.
Perhaps the source of our differences will become apparent if we examine the ends sought in defining bronchiolitis. My primary purpose in offering the criteria noted was to promote consistency in use of the term bronchiolitis for both patient care and research. These criteria lend themselves to reliability. They
McCONNOCHIE KM. Bronchiolitis-Reply. Am J Dis Child. 1983;137(8):806. doi:10.1001/archpedi.1983.02140340085026