Allergology & ENT & Family Medicine
Allergic rhinitis
Allergic rhinitis (AR) is an immunoglobulin E (IgE)-mediated inflammation of the nasal mucosa - a type I hypersensitivity reaction according to the Gell and Coombs classification - triggered by exposure to inhaled allergens in previously sensitized individuals, clinically characterized by the classic tetrad of watery rhinorrhea + salvo sneezing + nasal and ocular pruritus + nasal obstruction. With a prevalence of 15 to 25 % of the adult population in Canada and up to 30 to 40 % in school-age children - the majority of whom in Quebec suffer from allergy to pollens (birch + ragweed + grass) and house dust mites - allergic rhinitis is the most common chronic upper respiratory disease and one of the main causes of consultation in primary care. It is closely linked to allergic asthma (30 to 40 % of allergic rhinitis sufferers have bronchial asthma + uncontrolled rhinitis aggravates asthma + «one airway, one disease» concept), allergic conjunctivitis (co-present in 60 to 80 % of cases), chronic sinusitis and seromucous otitis, warranting integrated management. The ARIA classification (Allergic Rhinitis and its Impact on Asthma - updated 2020) classifies allergic rhinitis as intermittent (symptoms < 4 days/week or 4 consecutive weeks), and as mild (no impact on activities) or moderate to severe (with impact on sleep + school/professional activities + leisure), guiding treatment decisions according to a tiered algorithm. Available treatments - environmental control + 2nd-generation antihistamines + intranasal corticosteroids + leukotriene antagonists + specific allergen immunotherapy - enable satisfactory symptom control in the vast majority of cases, and subcutaneous or sublingual immunotherapy represents the only disease-modifying treatment (desensitization) capable of inducing lasting allergen tolerance.
Allergens and Seasonality in Quebec
- Tree Pollen (April–May): birch (Betula) ++ = most frequent pollen allergen in Quebec + alder + poplar + maple + ash + possible food cross-reactivity (oral allergy syndrome to stone fruits + apple + carrot + celery)
- Grass pollens (June–July): Timothy (Phleum pratense) + orchard grass + ryegrass + rhinitis + summer conjunctivitis + cross-reactions with certain cereals
- Ragweed (Ambrosia artemisiifolia — late August–October): Major cause of fall seasonal rhinitis in Quebec + very powerful allergen + northward geographic expansion linked to climate change + increasingly early seasonality
- House dust mites (Dermatophagoides pteronyssinus + D. farinae): main cause of perennial rhinitis + feed on human dander + proliferate in mattresses + pillows + carpets + stuffed animals + ideal relative humidity 70–80% % + peak in autumn-winter in closed heated homes
- Molds (Alternaria + Cladosporium + Aspergillus): Perennial rhinitis, aggravated in autumn (decomposing leaves), indoors (humidity + basement), outdoors (vegetation).
- Domestic animals (cats ++ dogs + rodents + rabbits): allergens carried by saliva proteins + dander + urine + Fel d1 (cat allergen) = most powerful and persistent allergen in the environment (remains for months in a cat-free home)
Clinical diagnosis and allergy testing
- Clinical diagnosis: Characteristic tetrad (watery rhinorrhea + ≥ 5 consecutive paroxysmal sneezes + nasal pruritus + nasal obstruction) + frequent association with allergic conjunctivitis (ocular pruritus + tearing + redness + chemosis) + seasonality or clear exposure relationship + personal or family history of atopy (asthma + eczema + food allergy) + on examination: pale or bluish nasal mucosa (unlike the bright red of infectious rhinitis) + enlarged inferior turbinates
- Skin tests (prick tests): Reference method for identifying responsible allergens + application of a drop of each allergenic extract to the forearm + superficial prick with a lancet + reading at 15–20 minutes + wheal ≥ 3 mm above negative control = positive + high sensitivity and specificity (85–95 %) + must be performed by an allergist or trained physician + stop antihistamines 5–7 days prior
- Serum specific IgE (RAST — RadioAllergoSorbent Test + ImmunoCAP): Dosage of serum IgE against specific allergens + useful if prick tests are impossible (dermographism + extensive eczema + continuous antihistamine use) + results in IU/mL with intensity classes (class 0 = negative + class 1-6 depending on intensity) + less sensitive than prick tests for certain allergens + variable correlation with clinical symptoms
- Total serum IgE: often elevated in allergic rhinitis but non-specific (also elevated in parasitic infections, certain IDs, certain medications) + not very useful on their own for diagnosis
- Specific nasal challenge test: intranasal administration of the suspected allergen → measurement of the response (rhinomanometry + PNIF) + indicated if there is a discrepancy between clinical presentation and skin tests + rarely used in routine practice
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Oral Allergy Syndrome (OAS) - also known as pollen-food syndrome - is an oral allergic reaction (itching + tingling + swelling of the lips + tongue + palate) triggered by the consumption of certain fresh foods in patients sensitized to corresponding pollens, due to cross-reactivity between pollen and food proteins. People allergic to birch frequently develop a reaction to apples + pears + cherries + peaches + apricots + kiwis + carrots + celery + raw hazelnuts - the proteins are denatured by heat → cooked foods are often well tolerated.
Processing — tiered algorithm (ARIA 2020)
| Bearing | Recommended Treatment | Notes and efficacy |
|---|---|---|
| Level 1 — Slight intermittent | 2nd generation oral antihistamine as needed (loratadine 10 mg + cetirizine 10 mg + fexofenadine 120–180 mg + desloratadine 5 mg + bilastine 20 mg) + or intranasal antihistamine (azelastine – fast acting in 15 min) | Second-generation antihistamines: little to no sedation + long duration of action (24 hours) + effective for rhinorrhea + sneezing + itching + LESS effective for nasal obstruction + first-generation antihistamines (diphenhydramine + chlorpheniramine) should be avoided (sedation + cognition + anticholinergic effects) |
| Stage 2 — Mild persistent or moderate intermittent | Daily intranasal corticosteroid (INC) → fluticasone (Flonase® + Avamys®) + mometasone (Nasonex®) + budesonide (Rhinocort®) + beclomethasone + or combination oral antihistamine + INC | CIN = most effective treatment for ALL nasal symptoms (rhinorrhea + obstruction ++ + sneezing + itching) → better reduction of nasal obstruction than antihistamines + onset of action 12–48 hours (maximum effect in 2 weeks) + very low systemic absorption → excellent long-term safety + DO NOT stop after a few days (maintenance treatment) |
| Level 3 — Persistent moderate to severe | Corticosteroid nasal + oral antihistamine + or combination of corticosteroid nasal + intranasal antihistamine (azelastine/fluticasone — Dymista®) + montelukast (Singulair® 10 mg — leukotriene antagonist) if asthma is associated | The combination of CIN + antihistamine provides additional benefit + Dymista® spray (azelastine + fluticasone in 1 spray) = superior to the two separate components + montelukast: modest efficacy on nasal symptoms + but benefit on concomitant asthma + neuropsychiatric effects reported (nightmares + depression — monitor) |
| Environmental control (all levels) | Mites: Waterproof mattress covers + pillows + wash laundry at 60°C + reduce humidity + Cats: Do not acquire a cat + if a cat is already present → cleaning + surface washing + HEPA filtration + Pollen: Close windows during pollination season + wear glasses + shower after exposure + monitor pollen counts | Environmental control measures → reduction of antigenic exposure → reduction of allergen dose → clinical improvement + anti-mite measures require rigorous application to be effective + combining multiple measures is more effective than a single one |
| Specific allergen immunotherapy | Subcutaneous (SCIT): monthly injections of increasing doses of allergen extracts x 3–5 years + sublingual (SLIT): daily tablets or drops x 3–5 years (grasses — Grazax® + Itulazax® + birch — Itulazax®) + mites — Actair® + Acarizax® | disease-modifying treatment → induces durable immunological tolerance (persists after discontinuation) → reduces symptoms + medication use + prevents the development of new sensitizations + prevents progression to asthma (Preventall) + indications: moderate to severe uncontrolled rhinitis + well-identified allergens + motivated patient + contraindications: severe uncontrolled asthma + severe heart failure |
Specifics in Children and Pregnant Women
- Child Intranasal corticosteroids are safe and recommended from age 2 + cetirizine and loratadine approved from age 2 + low-dose CINs have no effect on growth at usual therapeutic doses + immunotherapy can be initiated from age 5 + treating allergic rhinitis in children reduces the risk of developing asthma
- Pregnancy: Frequent pregnancy rhinitis (non-allergic – hormonal effect) + if allergic rhinitis: loratadine + cetirizine = preferred options (reassuring data) + low-dose intranasal corticosteroids (budesonide = best safety in studies) + avoid systemic decongestants (pseudoephedrine + phenylephrine) in the 1st trimester + ongoing immunotherapy can be continued but desensitization should not be started during pregnancy
Medical consultation recommended
Consult a doctor if allergic rhinitis symptoms are severe and not controlled by over-the-counter antihistamines, or if they are accompanied by wheezing shortness of breath (asthma), recurrent sinusitis, or recurrent otitis media with effusion. A comprehensive allergological evaluation with skin tests is recommended to identify the responsible allergens and consider desensitizing immunotherapy. For the prescription of intranasal corticosteroids and referral to allergology, Clinique Omicron offers consultations at its service points in Quebec and via telemedicine. To make an appointment, visit cliniqueomicron.ca.
Consult at Clinique Omicron
Clinique Omicron's nurse practitioners and physicians diagnose allergic rhinitis through history and clinical examination, prescribe second-generation antihistamines and intranasal corticosteroids according to the ARIA step-up approach, advise on environmental control measures tailored to suspected allergens, refer to allergists for skin testing and immunotherapy in moderate to severe uncontrolled cases, and assess and treat associated comorbidities (asthma, sinusitis, nasal polyposis). Consultations are available at multiple service points in Quebec and via telemedicine. To book an appointment, visit cliniqueomicron.ca.
The content of this page is provided for informational purposes only and does not replace the advice of a doctor or allergist. Precise diagnosis of the responsible allergens by skin prick tests or specific IgE is essential before initiating specific allergen immunotherapy (desensitization) – the only treatment that modifies allergic rhinitis. First-generation antihistamines (available over-the-counter) are not recommended due to their sedative effects and impact on cognition.
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