Allergic Rhinitis

Introduction

Allergic rhinitis is inflammation of the epithelial lining of the nose.

It is an extremely common condition seen regularly by both general practitioners and in ear nose and throat (ENT) clinics. It is estimated that allergic rhinitis affects 1 in 5 people in the United Kingdom.¹

Aetiology

Allergic rhinitis typically affects the nasal passages but can affect the entire upper respiratory tract. Symptoms are most often due to an IgE-associated response to common indoor and outdoor allergens. Examples of allergens include pollen, dust mites, mould, cigarette smoke and animal skin flakes.²

Additionally, prolonged occupational or recreational exposure to proteins not commonly associated with an allergic response can occur. For example, woodworkers becoming sensitised to wood dust and food workers sensitised to grain dust.²

Allergic rhinitis is traditionally divided into seasonal and perennial forms. The more modern classifications of allergic rhinitis take into account the spectrum of severity; ranging from mild and intermittent up to persistent and severe; with the associated impact on sleep, school/work performance and daily activities.^3,4

Risk factors

There may be a personal or family history of atopy often as a triad of asthma, eczema and allergic rhinitis.

Clinical features

History

Typical symptoms of allergic rhinitis include:⁴

• Nasal symptoms: sneezing, itching, discharge (rhinorrhoea), hyposmia (reduced sense of smell) and congestion.
• Eye symptoms: itching, watering, redness.
• Additional symptoms: postnasal drip, coughing, itching of palate or ears.
• Chronic nasal congestion: snoring, mouth breathing, halitosis.
• Bilateral symptoms within minutes of allergen exposure.

Other important areas to cover in the history include:⁵

• Type, frequency and persistence of symptoms.
• Location (indoors or outdoors).
• Severity and impact on quality of life (including sleep, concentration, impact on school or work).
• Housing conditions, pets and occupation: to identify possible causative triggers and allergens.
• Occupational history should include nature of the job, duration of employment before symptoms developed, agents exposed to at work, any improvement in symptoms when away from work.
• Associated atopic symptoms, asthma/wheeze, eczema or family history of such. Asthma and allergic rhinitis often co-exist. Good control of allergic rhinitis can have an impact on asthma symptoms.
• Previous treatments tried and their effectiveness.

Clinical examination

In cases of suspected allergic rhinitis, a nasal examination should be performed.

Typical clinical findings in allergic rhinitis are shown below.

External/general

• Nasal intonation of the voice
• “Allergic shiners” – darkened eye shadows under lower eyelids due to chronic congestion
• Erythematous conjunctiva with watering eyes may be evident

Internal nasal examination

• Nasal mucosa swelling with greyish discolouration
• Check for inflammatory nasal polyps (soft yellow swellings between the nasal septum and turbinates), hypertrophic nasal turbinates (soft pink swelling arising from lateral nasal wall), malignant growths (normally unilateral and suggested by hard/dark appearance, irregular surface and/or ulceration) or foreign bodies
• Purulent nasal discharge is more suggestive of infective rhinitis or sinusitis

Differential diagnoses

The largest discrete subsection to consider is that of non-allergic rhinitis. Table 1 gives an overview of the subtypes of non-allergic rhinitis.

Table 1. An overview of the causes of non-allergic rhinitis.

In addition, there are some further causes of rhinitis listed in the table below.

Table 2. An overview of alternative causes of rhinitis

Investigations

If the classic features of allergic rhinitis are present then the diagnosis is usually made clinically without the need for investigations.

Investigations to consider may include:

• Trial of antihistamines and/or intranasal corticosteroid: can be performed easily in primary care.
• Allergen skin-prick testing: if the allergen not easily identified from the history.
• In vitro specific IgE determination: some specialists may use this in identifying symptom trigger.

Testing of the sense of smell and nasal airflow (e.g. rhinomanometry) are rarely used outside of research settings.

Management

Conservative

Conservative measures depend on the underlying aetiology of the patient’s allergic rhinitis.

All patients should be offered information regarding the condition. For example, Allergy UK provides an online factsheet for patients.

Additionally, some patients may find nasal irrigation with saline useful. Devices for this purpose can be bought over the counter.

Table 3. Conservative management strategies for allergic rhinitis.

Medical

Mild disease

• 1^st line: oral antihistamine (e.g. loratadine or cetirizine). Less sedating antihistamines are available for patients who are significantly affected.
• 2^nd line: intranasal corticosteroids (see moderate/severe disease section)
• Adjuvant treatment: intranasal antihistamine (e.g. azelastine). Intranasal preparations have been shown to have a faster onset of action and are more effective than oral forms.⁴

Moderate or severe disease

Intranasal corticosteroids can be considered for moderate or severe allergic rhinitis. Options include beclomethasone (e.g. Beconase), mometasone (e.g. Nasonex) and fluticasone (e.g Flixonase, Avamys). Advise patients that the maximum effect can occur after 2 weeks of use. Patients with seasonal rhinitis should commence treatment before symptoms start.

Intranasal corticosteroids are usually administered as a nasal spray, though drops are also available. The dose should be monitored in children to avoid affecting growth.

A recent addition to the market is a combined topical corticosteroid and topical antihistamine spray (Dymista).

Other treatments for more severe cases include systemic corticosteroids (intra-muscular injection or a short course of oral steroids) or immune therapy (a course of subcutaneous or sublingual treatment). Leukotriene receptor antagonists (e.g. montelukast) are considered in patients with concomitant asthma.

When to refer to ENT

A 2-week wait (urgent) referral to ENT should be made if there are red flag symptoms suggestive of malignancy. These include unilateral symptoms of blood-stained discharge, nasal pain or recurrent epistaxis.

Routine referral should be considered for patients with persistent symptoms despite optimal management in primary care or if the diagnosis uncertain.

Surgery is not a treatment for allergy but is sometimes used (e.g. septoplasty, turbinate reduction) to improve the administration of topical therapies.

Complications

Chronic poorly controlled allergic rhinitis leads to chronic inflammation of the nasal mucosa and associated obstructive features and complications. These can include an increased predisposition to acute or chronic sinusitis, otitis media (due to eustachian tube occlusion), obstructive sleep apnoea and upper respiratory tract infections.⁷

Key points

• Allergic rhinitis is a common condition that affects up to 1 in 5 people in the UK.
• The classical features are sneezing, nasal discharge, itching and congestion.
• Allergic rhinitis is part of the triad of atopy (eczema, asthma and allergic rhinitis).
• Good control of allergic rhinitis is important in concomitant asthma symptom control.
• Conservative measures include allergen avoidance and nasal rinsing.
• Medical management includes oral or intranasal antihistamines and topical corticosteroids.
• Urgent ENT referral if red flag symptoms of unilateral bleeding, discharge and pain.
• Consider routine ENT referral if persistent symptoms despite best medical therapy or unclear diagnosis.

Editor

Mr Stephen Broomfield

Consultant ENT Surgeon, Bristol Royal Infirmary

Editor

Dr Chris Jefferies

References

1. NHS Patient Info. Allergic Rhinitis. Published in April 2019. Available from: [LINK].
2. BMJ Best Practice. Allergic Rhinitis. Updated April 2020. Available from: [LINK].
3. T. Clark. BSACI guideline for the diagnosis and management of allergic and non-allergic rhinitis. Revised edition published 2017
4. NICE CKS. Allergic Rhinitis. Published September 2018. Available from: [LINK].
5. J. Schunemann. Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines. Revised edition published 2016
6. Bunnag C, Jareoncharsri P, Tansuriyawong P, Bhothisuwan W, Chantarakul N. Characteristics of atrophic rhinitis in Thai patients at the Siriraj Hospital. Rhinology;37(3):125–130. Published 1999
7. DP Skoner. Complications of Allergic Rhinitis. Journal of Allergy and Clinical Immunology. Published June 2000. Available from: [LINK].