Allergic rhinitis is a common manifestation of atopy that significantly reduces quality of life. A careful history and examination, along with appropriate investigations, are needed to determine the most likely allergens and to direct treatment. Recent advances in allergen immunotherapy show promise and the ‘thunderstorm asthma’ phenomenon emphasises the need for action plans for patients with comorbid asthma.
- Allergic rhinitis creates a significant burden for affected individuals and reduces their quality of life.
- There are a broad range of differential diagnoses for allergic rhinitis, and an allergic cause for symptoms should be confirmed to direct treatment accordingly.
- There is limited evidence for the efficacy of allergen-avoidance strategies, but this may be due to the heterogeneity of the advice.
- Intranasal corticosteroids and oral antihistamines are considered first-line therapies.
- If symptoms are poorly controlled with simple strategies, referral to an allergist for possible allergen immunotherapy should be considered.
Allergic rhinitis (AR), or ‘hayfever’, is a common medical problem that can affect quality of life and restrict activities of daily living.1 Studies show a prevalence of 20 to 48% in the Australian population.2-4 AR may also involve other complications, including predisposition to upper respiratory tract infections, asthma development, sinusitis, reduced mood and cognition, school and work absenteeism, and negative impacts on speech and hearing development.5-7 It is a major risk factor for asthma. The Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines determine the severity of AR based on its frequency of symptoms (intermittent versus persistent) and impact on work, function and sleep, and show that severity of symptoms influences escalation of treatment.8,9
Typical symptoms of AR include conjunctivitis, nasal congestion, rhinorrhoea, pruritic throat and sneezing. Pollens from grasses, trees and weeds are common triggers for seasonal AR. Triggers for perennial AR include house dust mites (HDMs), cockroaches, animal dander (e.g. cat or dog) and mould. Australian studies have shown that HDMs, perennial ryegrass Timothy and, plantain and Bahia grasses are among the most common allergens to which patients are sensitised on skin prick testing (SPT), and many patients are polysensitised to allergens.10,11
AR exists on the spectrum of atopy. This includes the disorders of asthma and eczema and appears to be on the rise in both developed and developing countries.12 About one-half to two-thirds of patients with rhinitis symptoms are atopic.13,14 Although symptoms of AR are triggered by allergens, there is a separate nonallergic entity which has many causes that can be elicited by careful history, examination and investigations.15 These disorders are managed according to their aetiology but can be broadly grouped under the umbrella term of nonallergic rhinitis. Differential diagnoses to consider for patients with rhinitis symptoms are listed in the Box.