Positioning of antihistamines in the Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines

Abstract

Allergic rhinitis (AR) is a major health problem with high and ever-increasing prevalence worldwide. At least one-fifth of adults in industrialized countries are estimated to have AR, defined as nasal and eye symptoms that are sufficiently severe to have a substantial negative impact on the quality of life (QoL). The former classification of AR comprised seasonal AR (SAR) and perennial AR (PAR), which did not adequately reflect the presentation and clinical course of the disease. The Allergic Rhinitis and its Impact on Asthma (ARIA) classification is based on the duration of symptoms and the disease severity. Both intermittent AR (IAR: symptoms ≤ 4 days/week or ≤ 4 consecutive weeks) and persistent AR (PER: symptoms > 4 days/week and > 4 consecutive weeks) may be mild, moderate, or severe based on the QOL impairment (sleep, daily activities/leisure, work productivity/school performance) and bothersome symptoms. Despite its disabling effects, AR remains a condition where affected individuals do not seek appropriate treatment, are undertreated and do not adhere well to treatment, which all lead to low disease control and high societal costs. The four pillars of AR treatment are allergen and pollutant avoidance, patient education, pharmacotherapy and allergen-specific immunotherapy. Oral antihistamines, together with intranasal corticosteroids and leucotriene antagonists, constitute important pharmacological options for the treatment of AR at all levels of severity. New second-generation antihistamines are H₁-receptor antagonists with high efficacy (rapid onset of action for AR symptoms, sometimes even on nasal congestion, improvement of QoL and additional anti-allergic effects) and safety (low sedation rates). Although new antihistamines have been studied and approved for SAR and PAR, only some of them have been reported to show efficacy and safety for treatment of AR under the ARIA classification: levocetirizine (high efficacy) and rupatadine (dual antihistamine and anti-PAF effects) for PER, and desloratadine (high safety) for both IAR and PER.