Rhinovirus and asthma: a storied history of incompatibility.

The human rhinovirus (HRV) is commonly associated with loss of asthma symptom control requiring escalation of care and emergency room visits in many patients. While the association is clear, the mechanisms behind HRV-induced asthma exacerbations remain uncertain. Immune dysregulation via aberrant immune responses, both deficient and exaggerated, have been proposed as mechanisms for HRV-induced exacerbations of asthma. Epithelium-derived innate immune cytokines that bias Th2 responses, including interleukin (IL)-25, IL-33, and thymic stromal lymphopoietin (TSLP), have also been implicated as a means to bridge allergic conditions with asthma exacerbations. In this review, we discuss the literature supporting these positions. We also discuss new and emerging biotherapeutics that may target virus-induced exacerbations of asthma.