Allergic rhinitis: A clinical update

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Reference: March-April 2026 | Issue 2 | Vol 19 | Page 28

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An immunoglobulin E-mediated hypersensitivity reaction to inhaled environmental allergens that impacts various aspects of a person’s life

Allergic rhinitis is a common chronic inflammatory disorder of the nasal mucosa, affecting a significant proportion of the Irish population and frequently presenting in general practice. Despite its common occurrence, allergic rhinitis is often underestimated in terms of clinical significance, leading to underdiagnosis and suboptimal management.

The condition has a significant impact on quality of life, sleep, cognitive function, and work productivity, and is closely associated with asthma and other upper airway disorders. Effective recognition and management in primary care are important to optimise patient outcomes and reduce long-term morbidity.^{1, 2}

Pathophysiology

Allergic rhinitis is an immunoglobulin (Ig) E-mediated hypersensitivity reaction to inhaled environmental allergens such as grass and tree pollens, house dust mite, mould spores, and animal dander. Initial exposure leads to sensitisation, with production of allergen-specific IgE antibodies.

On subsequent exposure, allergen-induced cross-linking of IgE on mast cells in the nasal mucosa triggers degranulation and release of inflammatory mediators including histamine and leukotrienes. This early-phase response results in sneezing, nasal itching, rhinorrhoea, and congestion. A subsequent late-phase response, dominated by eosinophilic infiltration and sustained inflammation, contributes to mucosal oedema, ongoing nasal obstruction, and persistent symptoms.^{1, 2,3}

Clinical presentation

Clinically, allergic rhinitis presents with a range of nasal and ocular symptoms that may vary in severity and frequency. Patients commonly report paroxysmal sneezing, nasal itching, watery rhinorrhoea, and nasal congestion, often accompanied by itchy, red or watery eyes. Postnasal drip, throat clearing, cough, and impaired sense of smell may also occur.

Fatigue, poor sleep quality, and reduced concentration are frequently reported, particularly in those with persistent disease. Symptoms may follow a seasonal pattern, particularly in pollen-mediated disease, or may be perennial when exposure to allergens such as house dust mite is continuous.^{1, 2}

Classification

The classification of allergic rhinitis has evolved to better reflect symptom burden and disease impact. The Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines classify the condition according to symptom duration and severity rather than seasonal terminology. Disease is described as intermittent when symptoms occur for fewer than four days per week or for less than four consecutive weeks, and persistent when symptoms exceed these thresholds.

Severity is categorised as mild or moderate to severe depending on the presence of sleep disturbance, impairment of daily activities, reduced work or school performance, and overall quality of life impact. This classification is particularly useful in guiding treatment decisions in primary care.³

Diagnosis

Diagnosis of allergic rhinitis is primarily clinical and based on a thorough history and physical examination. A personal or family history of atopic disease, including asthma or eczema, supports the diagnosis. On examination, patients may be observed breathing through the mouth, frequently sniffing or clearing their throat. Dark circles under the eyes, known as allergic shiners, and a horizontal crease across the bridge of the nose caused by repeated rubbing may be present, particularly in children.

Inspection of the nasal passages usually shows swollen nasal lining with clear, watery discharge. The inferior turbinates may appear pale or bluish, and the nasal mucosa can have a cobblestone appearance. Where available, nasal endoscopy can help identify nasal polyps or structural abnormalities.

Palpation of the sinuses may cause tenderness in patients with chronic symptoms. Assessment should also include screening for associated conditions such as asthma and atopic dermatitis, and asking about aspirin sensitivity. IgE can be useful in confirming allergen sensitisation, particularly where the diagnosis is uncertain or when allergen-specific immunotherapy is being considered.^4,5,6

Differential diagnoses

A number of differential diagnoses should be considered when assessing patients with chronic nasal symptoms. Non-allergic rhinitis presents with similar symptoms but lacks an immunological basis and is often triggered by irritants such as smoke, strong odours or temperature changes. Infective rhinosinusitis should be suspected in the presence of purulent nasal discharge, facial pain, fever or systemic symptoms.

Structural abnormalities including nasal septal deviation, turbinate hypertrophy, and nasal polyposis may cause persistent obstruction. Medication-induced rhinitis, particularly rhinitis medicamentosa resulting from prolonged use of topical nasal decongestants, is an important and preventable cause of chronic nasal congestion.^5,6

The impact of allergic rhinitis extends beyond nasal symptoms. There is a well-established association between allergic rhinitis and asthma, reflecting the concept of a united airway disease.⁶ Poorly controlled allergic rhinitis is associated with worsened asthma control, increased exacerbations, and higher healthcare utilisation.

Effective management of allergic rhinitis has been shown to improve asthma outcomes, highlighting the importance of integrated airway management in primary care. In children and adolescents, allergic rhinitis may adversely affect school performance, behaviour, and sleep, while in adults it is associated with reduced work productivity and increased absenteeism.^1,2,6

Treatment and management

Management of allergic rhinitis in general practice is centred on patient education, allergen avoidance where feasible, and evidence-based pharmacotherapy. While complete avoidance of airborne allergens is rarely achievable, practical measures such as minimising outdoor exposure during high pollen counts, keeping windows closed, using saline nasal irrigation, and avoiding tobacco smoke can help reduce symptom burden.

Education regarding the chronic nature of the condition and the need for regular rather than intermittent treatment is essential to improve adherence and outcomes.^1,2,5

Pharmacological treatment should follow a stepwise approach guided by symptom severity and persistence. Second-generation, non-sedating oral antihistamines are effective in mild intermittent disease, particularly for relief of sneezing, itching, and rhinorrhoea.

However, they are less effective for nasal congestion. Intranasal corticosteroids are the most effective monotherapy for moderate to severe or persistent allergic rhinitis due to their potent anti-inflammatory effects on the nasal mucosa. Regular use – rather than as-needed dosing – is required for optimal efficacy, and correct administration technique should be demonstrated and reinforced by healthcare professionals.^1,2,6

For patients with inadequate symptom control, combination therapy may be required. Intranasal antihistamines may be used alone or in combination with intranasal corticosteroids to provide rapid symptom relief. Leukotriene receptor antagonists may offer additional benefit in patients with coexisting asthma, although they are generally less effective than intranasal corticosteroids for nasal symptoms.

Short-term use of topical or oral decongestants may provide temporary relief of severe congestion, but prolonged use should be avoided due to the risk of rebound congestion and systemic adverse effects.^1,5,6

Allergen immunotherapy may be considered in selected patients with confirmed allergen sensitisation who have persistent symptoms despite optimal pharmacotherapy. Both subcutaneous and sublingual immunotherapy have been shown to reduce symptom severity, medication requirements, and long-term disease progression. This treatment is typically initiated and supervised in specialist settings and requires a long-term commitment from the patient.^1,2,6

Complications

Chronic rhinosinusitis is a recognised complication of allergic rhinitis, although it remains a distinct clinical entity. It is defined by persistent inflammation of the nasal and sinus mucosa, with symptoms such as nasal blockage and nasal discharge lasting longer than 12 weeks. Ongoing inflammation may lead to the development of nasal polyps, which arise from the chronically inflamed mucosa of the paranasal sinuses.

These polyps are typically benign and occur bilaterally – the presence of unilateral polyps should prompt further investigation to exclude malignancy. Nasal polyps affect approximately four per cent of the general population and are more frequently observed in males. First-line management includes intranasal corticosteroids and saline irrigation, while surgical intervention is generally reserved for individuals who fail to respond to optimal medical treatment.⁶

Allergic sensitisation in allergic rhinitis can also influence immune activity within the adenoids, leading to adenoidal hypertrophy, particularly in children. Dysfunction of the eustachian tube is commonly associated with allergic rhinitis and may present with symptoms such as a sensation of ear fullness, intermittent ear pain, or popping sensations.

There is a well-established association between allergic rhinitis and asthma, with studies indicating that between 10 and 40 per cent of individuals with allergic rhinitis also have asthma. The risk appears to be higher in those with moderate to severe persistent rhinitis, and allergic rhinitis has been identified as an independent risk factor for the later development of asthma, especially when diagnosed in early childhood.

Additional conditions associated with allergic rhinitis include otitis media with effusion, chronic cough, and eosinophilic oesophagitis, although the precise mechanisms linking these conditions require further clarification.⁶

Allergen immunotherapy, while effective for selected patients with allergic rhinitis, carries a small risk of adverse reactions. Patients may experience transient worsening of rhinitis or asthma symptoms following treatment and, in rare cases, systemic reactions including anaphylaxis can occur.

It is therefore important that healthcare professionals involved in administering allergen immunotherapy are trained in the recognition and management of severe allergic reactions and have immediate access to emergency medications, including adrenaline, as well as appropriate airway management equipment.⁶

Prevention

Prevention of allergic rhinitis focuses on reducing exposure to known allergens and modifying environmental and behavioural risk factors where possible. Although complete avoidance of airborne allergens such as pollens is often impractical, lifestyle and environmental measures can help to decrease overall allergen contact and may reduce symptom burden.

Strategies include maintaining indoor environments with lower humidity to limit dust mite and mould growth, using allergen-impermeable bedding covers, implementing high-efficiency particulate air (HEPA) filtration, and keeping windows closed during peak pollen periods, as supported by evidence on environmental control measures and allergen exposure reduction.⁸

In addition to environmental control, allergen immunotherapy administered over several years in appropriately selected patients with moderate to severe allergic rhinitis has been shown to not only improve symptoms but also prevent progression to asthma, particularly in children and adolescents sensitised to grass or birch pollens, indicating a disease-modifying preventive approach.⁹

Role of the nurse in the management of allergic rhinitis

Nurses play a central role in the effective assessment and ongoing management of allergic rhinitis within primary care. They are often the first point of contact for patients presenting with nasal and upper airway symptoms and are therefore well placed to undertake comprehensive symptom assessment, identify potential allergen triggers, and evaluate the impact of symptoms on daily functioning, sleep quality, and work or school performance.

Through structured history taking and regular review, nurses can help distinguish allergic rhinitis from other causes of chronic nasal symptoms and support timely diagnosis.^1,7

Patient education is a key component of nursing care in allergic rhinitis. General practice nurses provide practical guidance on allergen avoidance strategies, reinforce the importance of regular rather than intermittent treatment, and address common misconceptions regarding medication use, particularly concerns about intranasal corticosteroids.

Demonstration and reinforcement of correct nasal spray technique is important, as poor technique is a common cause of treatment failure. Nurses also support patients using inhaled therapies for co-existing asthma, ensuring correct inhaler technique and promoting adherence to treatment plans.^1,7

Monitoring response to treatment and identifying suboptimal symptom control are important aspects of the nursing role. Through scheduled reviews, nurses can assess symptom improvement, side effects, and medication adherence – and escalate care when first-line therapies are ineffective. General practice nurses are instrumental in identifying patients who may benefit from referral for specialist assessment, including those with persistent symptoms despite optimal therapy or those being considered for allergen immunotherapy.^1,7

Recognition of red-flag symptoms is necessary to ensure safe practice. Features such as unilateral nasal obstruction, recurrent or unexplained epistaxis, suspected nasal polyposis, facial pain, anosmia or systemic symptoms should prompt further investigation and referral to secondary care. By combining clinical vigilance with patient education and continuity of care, nurses play an important role in improving outcomes and quality of life for individuals living with allergic rhinitis.^1,7

Conclusion

Allergic rhinitis is a prevalent inflammatory condition that is commonly managed within general practice and has a substantial impact on physical health, sleep quality, and daily functioning. Although symptoms are often perceived as minor, inadequate control can lead to significant morbidity and the development of associated conditions, including asthma and chronic rhinosinusitis.

Early identification, accurate classification, and evidence-based management are essential to achieving effective symptom control. General practice nurses are integral to this process, supporting assessment, education, correct use of therapies, and ongoing monitoring.

By adopting a structured, patient-centred approach and recognising when specialist referral is required, primary care teams can deliver high-quality care and improve long-term outcomes for individuals with allergic rhinitis.