1. When to suspect allergic rhinitis

Allergic rhinitis is easily missed. Consider the possibility of allergic rhinitis in a patient with any of the following:

• Symptoms suggestive of continuous or recurrent upper respiratory tract infections
• Frequent sore throats
• Hoarse voice
• Persistent throat-clearing
• Persistent mouth breathing, especially in children with perennial rhinitis
• Snoring
• Feeling of pressure over sinuses
• Recurrent headaches
• Recurrent serous otitis media, especially in children
• Coughing, especially in children (e.g. those who habitually cough soon after lying down at night)
• Halitosis
• Poor sleep and daytime fatigue or poor concentration
• Loss of sense of smell
• Persistent respiratory symptoms despite stable, well controlled asthma, appropriate treatment and good lung function on spirometry.

Practice points

• Patients can mistake symptoms of allergic rhinitis for asthma. Allergic rhinitis is sometimes more easily recognised only after asthma has been stabilised.  
• The absence of classical symptoms does not rule out the diagnosis of allergic rhinitis. It may present as any combination of rhinorrhoea, itching/sneezing and blockage, including blockage alone. 
• Children with allergic rhinitis may show persistent throat-clearing but be unaware of nasal symptoms.

2. History

Ask about:

• symptoms (runny nose, sneezing, blocked nose, itchy/runny eyes)
• onset, duration and pattern of symptoms over the day or year (Table 1)
• family and personal history of allergic conditions, e.g. asthma, atopic dermatitis
• triggering and relieving factors
• use of medications (including complementary medications), adherence and response
• home, work and leisure environments
• any systemic symptoms (e.g. daytime fatigue).

! Further investigations/early referral (or specialist consultation where referral access is limited) may be indicated if any of these are present:

• Difficult-to-treat eczema, food allergies or poorly controlled asthma >> Consider referral to allergy specialist.
• Persistent rhinitis symptoms that have not responded to a trial of appropriate medications >> Consider referral to allergy specialist or ear, nose and throat surgeon (ENT).
• Persistent symptoms and signs suggesting chronic sinusitis (nasal obstruction, congestion, post nasal drip and a reduced sense of smell¹⁸) for 12 weeks or more >> Consider CT scan, referral to allergy specialist or ENT. >> Consider foreign body.
• Atypical symptoms that suggest an alternative diagnosis such as polyp, tumour, or foreign body (e.g. persistent unilateral bleeding, persistent unilateral obstruction) >> Consider referral to ENT.

Pharmacy practice points

• Advise people with asthma to consult their GPs for thorough investigation if:
• rhinitis symptoms are severe or not well controlled by INCS and antihistamines
• rhinitis treatment is required for more than 4 weeks at a time
• other medical conditions are present
• there are any complications, e.g. pain, hearing loss, loss of sense of smell.

3. Physical examination

Examine upper and lower airway for signs of rhinitis and for signs of asthma. In addition to the nasal cavity (including inspection of mucosa and septum), examine the eyes and orbital areas, ears and oropharynx, perform a thorough chest examination.

Further investigation should be considered if:

• asthma is suspected (or status of existing asthma control needs review) >> Perform pre-and post-bronchodilator spirometry.
• a unilateral polyp is present (see History) >> Consider referral to ENT.

The absence of abnormal findings does not exclude intermittent allergic disease.

Practice points

Both allergic and non-allergic rhinitis can respond to INCS.² Therefore response to INCS alone does not confirm allergy or warrant allergen avoidance measures in the absence of confirmed allergic triggers.

4. Confirm cause is predominantly allergic

• Try to distinguish allergic rhinitis from common non-allergic types (e.g. vasomotor rhinitis, bacterial and viral respiratory infections, sinusitis). Up to 80% of Australian young adults with rhinitis symptoms are atopic.¹⁹
• Rule out less common conditions, (e.g. overuse of topical decongestant sprays, nasal polyps, anatomical abnormalities, foreign bodies, adverse effects of medications, hormonal effects, sensitivity to drugs or occupational irritants, cocaine abuse) and rare conditions (e.g. tumours, granulomas, atrophic rhinitis, ciliary defects, cerebrospinal rhinorrhoea, vocal cord dysfunction).

Be aware that both allergic and non-allergic components may contribute to rhinitis in an individual.

Practice points

• Before contemplating allergen avoidance measures or discussing desensitisation therapy, confirm which allergens are clinically important. Consider referral to an allergist for detailed allergy assessment. 
• Tell patients:
  • Food allergies do not cause allergic rhinitis – nasal symptoms in reaction to food (e.g. spicy foods, wine) is not due to allergy but may indicate irritation or a chemical intolerance.
  • Rhinitis in response to fumes (e.g. fragrances and paints) is not an allergic reaction, though it may respond to INCS.

5. Initiate a therapeutic trial with INCS

Give INCS and monitor response in patients with:

• a provisional diagnosis of persistent allergic rhinitis
• no features requiring immediate referral or further investigations
• no contraindications to use of intranasal corticosteroids (severe nasal infection including candidiasis, haemorrhagic diathesis, history of recurrent nasal bleeding).

If symptoms do not resolve within a 3–4 weeks of commencing INCS, consider allergy testing and review the diagnosis.

If symptoms respond and long-term (>6 weeks) treatment is required, confirm a definitive diagnosis of allergic rhinitis through careful history and appropriate allergy testing.

Pratice points

Both allergic and non-allergic rhinitis can respond to INCS.² Therefore response to INCS alone does not confirm allergy or warrant allergen avoidance measures in the absence of confirmed allergic triggers.

6. Consider allergy testing, referral

Skin prick testing or blood tests for allergen-specific IgE (radioallergosorbent testing; RAST) may be necessary to identify triggers.

• These tests should be interpreted by a doctor trained in their interpretation. False negative and false positive results can occur.
• Refer to an allergist if triggers are in doubt.
• Most rural and remote areas can access RAST through major pathology laboratories.