Type 2 Inflammation of the Nasal Airway: impacts on the Laryngopharynx
Allergic rhinitis (AR) impacts approximately 40% of the general population [27 , 28 ]. In sensitised patients, exposure to airborne allergens triggers an IgE-mediated immune response, leading to mast cell de-granulation and release of inflammatory mediators like histamine. This culminates in nasal mucosal inflammation, resulting in clinical symptoms such as rhinorrhoea, sneezing, and nasal congestion. In patients with allergic rhinosinusitis (ARS), this reaction extends to the paranasal sinuses, and may result in additional symptoms of headache, facial pain and or fullness.
Table 1 summarises research data reporting the prevalence of chronic throat symptoms in this population. Beyond the nose, chronic cough is recognised as a potential sequelae of inflammatory nasal disease, including allergic nasal phenotypes. Refractory cough in this setting is often enveloped under the Upper Airway Cough Syndrome (UACS) umbrella, which links refractory cough without structural or other disease explanations with chronic nasal inflammation, of which allergy is a key aetiology[24-26 , 29 ]. We found non-cough aerodigestive symptoms are infrequently sought and minimally reported in the setting of allergic nasal disease, despite observations that refractory cough is often accompanied by additional localised throat symptoms[30 , 31 ]. Considering this limitation, it nonetheless would appear that non-specific complaints involving unexplained dysphonia, globus, mucus sensation, throat clearing and other irritative UCTS are equally prevalent in this cohort.