A review of allergic rhinitis

Allergic rhinitis (AR) is the most widespread type of non-infectious rhinitis. In 2001, the Allergic Rhinitis and its Impact on Asthma (ARIA) group classified AR as intermittent/persistent or mild/moderate-severe, based on the duration/chronicity and the severity of symptoms and the impact on patient’s quality of life. It is generally associated with co-morbid disorders such as conjunctivitis, sleep disturbances and obstructive sleep apnoea, with a severe impact on quality of life. The most relevant co-morbidity is asthma (38% of all AR patients present with asthma symptoms) in accordance with the recent definition of united airway disease (UAD). Pharmacotherapy must be considered as the cornerstone intervention and, particularly, antihistamines and intranasal corticosteroids. The treatment for AR is effective in the majority of patients, a remaining 20% do not achieve symptom control with an adequate pharmacological treatment; they suffer from severe chronic upper airway diseases (SCUADs). Specific immunotherapy (SIT) is considered the only curative treatment against AR. It reduces the clinical manifestations of the disease and drug consumption with a carry-over effect (long-lasting persistence of effects after discontinuation) and it seems to prevent the onset of new sensitisations, reducing the risk of asthma onset. Sublingual immunotherapy (SLIT) was first accepted as a viable alternative to subcutaneous immunotherapy (SCIT) in the 1998 World Health Organization (WHO) position paper; it is widely used in Europe and other countries, and registrative studies are ongoing in the US. Chemically altered allergens, allergoids, recombinant allergens and relevant T-cell epitope peptides are expected to be promising approaches for the future of SIT.