Over the last decade, there have been widespread efforts to reduce non-evidence-based therapies for viral bronchiolitis. We question whether this change in practice has inadvertently impacted the diagnosis and management of other pediatric lower-respiratory-tract illnesses. We used the Pediatric Health Information System (PHIS) and logistic regression to describe trends in relative diagnosis frequency of bronchiolitis, viral pneumonia, and reactive airway disease (RAD)/asthma as well as systemic corticosteroid use among children of the age range 1 to 4 years over a 10-year period. Among 169,207 children, the relative frequency of asthma/RAD diagnoses declined over a 10-year period, while bronchiolitis and viral pneumonia diagnoses increased among children of the age range 1 to 3 years and 2 to 4 years, respectively. Frequency of systemic corticosteroid use declined. We question whether the observed shift in diagnosis from asthma/RAD to bronchiolitis or viral pneumonia is reflective of true disease pathophysiology or if it represents an unintended consequence of campaigns surrounding bronchiolitis.