Allergic rhinitis: classification, diagnosis and treatment

Rhinitis is characterised by a combination of nasal symptoms including itching, sneezing, rhinorrhoea, and nasal congestion caused by inflammation of the nasal mucosa. When these symptoms are triggered due to allergen exposure, it is known as allergic rhinitis. Rhinitis symptoms can also be present in patients without any evidence of allergic triggers. This is known as non-allergic rhinitis and includes types such as infectious, occupational or drug-induced rhinitis (Bousquet et al, 2008; Scadding et al, 2017).

Allergic rhinitis is the most common form of rhinitis and is an immunoglobulin E (IgE)-mediated inflammatory disorder that occurs because of allergen exposure. Sneezing and rhinorrhoea are early symptoms of allergic rhinitis. These are caused by the release of histamine, prostaglandin and leukotriene by the activated mast cells in response to exposure to allergen. This is known as an early phase reaction. Nasal obstruction results from the remodelling of the nasal mucosa as a result of the late inflammatory phase (Bousquet et al, 2008; Scadding et al, 2017). Other symptoms derived from allergic rhinitis are tiredness and poor concentration. These symptoms have a large impact on patients’ quality of life by affecting their sleep, social life and work/school performance. Despite the reduction in patients’ quality of life, allergic rhinitis remains under-recognised (Bousquet et al, 2008; Scadding et al, 2017).