Postviral bronchial hyperreactivity syndrome: recognizing asthma's great mimic.

Although there are no prospective studies regarding the frequency of postviral bronchial hyperreactivity syndrome, it is a common complication of upper and lower respiratory tract viral infections. The respiratory symptoms closely resemble those of asthma, but they are present for only 3 weeks to 3 months following the acute infection phase. Defining the mechanisms of this syndrome may provide insight into the pathogenesis of asthma. Postviral bronchial hyperreactivity syndrome is frequently misdiagnosed and inappropriately managed because many physicians are unfamiliar with this illness. Because of its characteristic history, diagnosis is straightforward when the physician knows what to look for, and response to therapy is excellent. This report presents a case history followed by a review of the proposed mechanisms of bronchial hyperreactivity following viral respiratory infections. The clinical features and criteria for diagnosing postviral bronchial hyperreactivity syndrome are also discussed.