Nonallergic Rhinopathy: A Comprehensive Review of Classification, Diagnosis, and Treatment

Chronic nonallergic rhinitis (NAR) syndromes encompasses various conditions, of which vasomotor (VMR) rhinitis is the most common form representing approximately 80% of patients also referred to as nonallergic rhinopathy, nasal hyperreactivity, neurogenic rhinitis or idiopathic rhinitis. Expert panels have recommended replacing VMR terminology as it is more descriptive of this condition that is characterized by symptoms triggered by chemical irritants and weather changes through chemosensors, mechanosensors, thermosensors, and/or osmosensors activated through different Transient Receptor Potential (TRP) calcium ion channels. Elucidating the specific role of TRP Vanilloid 1 (TRPV1), triggered by capsaicin, has been an important advancement in better understanding the pathophysiology of non-allergic rhinopathy as it has now been shown that downregulation of TRPV1 receptors by several therapeutic compounds provides symptomatic relief for this condition. The classification of NAR is further complicated by its association with allergic rhinitis (AR) referred to as mixed rhinitis (MR), which involves both IgE-mediated and neurogenic mechanistic pathways. Comorbidities associated with non-allergic rhinopathy, including rhinosinusitis, headaches, asthma, chronic cough, and sleep disturbances, underscore the need for comprehensive management. Treatment options for non-allergic rhinopathy include environmental interventions, pharmacotherapy, and, in refractory cases, surgical options, emphasizing the need for a tailored approach for each patient. Thus, it is extremely important to accurately diagnose non-allergic rhinopathy, as inappropriate therapies lead to poor clinical outcomes and unnecessary healthcare and economic burdens for these patients. This review provides a comprehensive overview of NAR subtypes, focusing on classification, diagnosis, and treatment approaches for non-allergic rhinopathy.