How to differentiate and treat seasonal allergies versus sinus infection?

Differentiating and Treating Seasonal Allergies versus Sinus Infection

For patients presenting with nasal symptoms, distinguish allergic rhinitis from sinusitis by the presence of nasal itching, sneezing, clear rhinorrhea, and bilateral symptoms (allergic rhinitis) versus facial pain/pressure, purulent drainage, fever, and unilateral symptoms (sinusitis), then treat allergic rhinitis with intranasal corticosteroids as first-line therapy and sinusitis with antibiotics plus adjunctive measures to promote drainage. 1, 2

Key Distinguishing Features

Allergic Rhinitis Presentation

• Classic symptom tetrad: nasal itching, sneezing, clear rhinorrhea, and nasal congestion 1
• Ocular symptoms: itching and tearing of the eyes are highly suggestive of allergic etiology 1
• Palatal itching: itching of the nose and palate strongly indicates allergic cause 1
• Bilateral symptoms: affects both nasal passages equally 1
• Temporal pattern: seasonal symptoms during specific pollen seasons or perennial symptoms with year-round allergen exposure 1
• Physical examination: edematous and pale turbinates in seasonal allergic rhinitis; erythematous and inflamed turbinates with serous secretions in perennial allergic rhinitis 3

Sinusitis Presentation

• Facial pain or pressure: particularly over the cheeks and forehead, which is uncommon in pure allergic rhinitis 1
• Purulent nasal drainage: colored (yellow or green) rhinorrhea suggests bacterial infection 1
• Fever and myalgia: systemic symptoms point toward infectious etiology 1
• Unilateral symptoms: unilateral nasal blockage or rhinorrhea suggests sinusitis or other structural pathology 1
• Severe headache: more typical of sinusitis than allergic rhinitis 1
• Duration: viral upper respiratory infections produce similar symptoms but are shorter in duration 1

Red Flag Symptoms Requiring Further Investigation

• Epistaxis (nosebleeds) 1
• Unilateral rhinorrhea or nasal blockage 1
• Anosmia (loss of smell) 1
• Severe headache 1

These symptoms could indicate cerebrospinal fluid rhinorrhea, sinonasal tumors, or chronic rhinosinusitis and warrant additional workup. 1

Treatment of Allergic Rhinitis

First-Line Therapy: Intranasal Corticosteroids

Intranasal corticosteroids are the most effective single medication class for controlling all symptoms of allergic rhinitis, including nasal congestion, rhinorrhea, sneezing, and itching. 1, 4, 3

• Adults and children ≥12 years: Start with fluticasone propionate 2 sprays per nostril once daily (200 mcg total) or mometasone furoate 2 sprays per nostril once daily (200 mcg total) 5
• Children 4-11 years: Fluticasone propionate 1 spray per nostril daily (100 mcg total) 5
• Children 2-5 years: Triamcinolone acetonide 1 spray per nostril daily or mometasone furoate 1 spray per nostril daily 5, 4

Critical administration technique: Direct the spray away from the nasal septum using the contralateral hand technique to reduce epistaxis risk by four times. 5

Second-Line Options for Mild Symptoms

• Second-generation oral antihistamines (cetirizine, fexofenadine, desloratadine, loratadine) for mild intermittent allergic rhinitis with predominant sneezing and itching 3, 6
• Intranasal antihistamines (azelastine, olopatadine) as alternative monotherapy 3

Combination Therapy for Moderate-to-Severe Disease

For patients with moderate-to-severe allergic rhinitis not responding to intranasal corticosteroid monotherapy, add an intranasal antihistamine (azelastine) to the intranasal corticosteroid (fluticasone). 1, 7

• The combination provides >40% relative improvement compared to either agent alone 7
• Symptom score reductions of -5.31 to -5.7 with combination versus -3.84 to -5.1 with fluticasone alone 7

Medications to Avoid

• Leukotriene receptor antagonists (montelukast) are significantly less effective than intranasal corticosteroids and should not be used as primary therapy 1, 4
• First-generation antihistamines should be avoided due to sedative and anticholinergic effects 4
• Topical decongestants should be limited to 3 days maximum to avoid rhinitis medicamentosa 5

Treatment of Sinusitis

Primary Treatment: Antibiotics

Ampicillin or amoxicillin is the antibiotic of choice for bacterial sinusitis. 2

All patients with sinusitis should receive antibiotics to eliminate infection and encourage drainage. 2

Adjunctive Measures to Promote Drainage

• Oral and topical decongestants to facilitate drainage through the sinus ostia 8
• Fluids and expectorants to thin secretions 2
• Intranasal corticosteroids (flunisolide, fluticasone, mometasone) for patients with marked rhinitis, nasal polyps, or swollen mucosa to decrease inflammation and promote drainage 2, 8
• Steam inhalations and saline irrigations to promote ciliary function 8

Role of Antihistamines in Sinusitis

Antihistamines are indicated for acute sinusitis ONLY when a patient has concomitant allergies that are symptomatic during allergy season or after infection has been ruled out as the primary cause. 8

Antihistamines can thicken secretions and impair drainage in acute bacterial sinusitis without an allergic component. 8

Common Clinical Scenarios

Allergic Rhinitis Complicated by Sinusitis

Sinusitis is a common complication of allergic rhinitis, occurring when inflammation of the nasal mucosa leads to obstruction of the sinus ostia and creates favorable conditions for bacterial growth. 2, 9

• Treat both conditions simultaneously: antibiotics for infection plus intranasal corticosteroids to reduce inflammation and promote drainage 2
• As many as half of patients with sinusitis have marked rhinitis requiring topical steroids 2

Mixed Rhinitis

Mixed rhinitis (combined allergic and nonallergic rhinitis) occurs in 44% to 87% of patients with allergic rhinitis and is more common than either pure form. 1

These patients require intranasal corticosteroids as the foundation of therapy, as they address both allergic and inflammatory components. 1

Important Caveats

• Family history of atopy strengthens the diagnosis of allergic rhinitis 1
• Medication review is essential, as antihypertensive drugs, psychotropic agents, and topical decongestants can cause nasal symptoms 1
• Allergy testing (skin or blood specific IgE) should be performed when diagnosis is uncertain or when patients do not respond to empiric treatment 1
• Long-term safety: Intranasal corticosteroids are safe for indefinite use at recommended doses, with no effect on growth in children or hypothalamic-pituitary-adrenal axis function 5
• Onset of action: Intranasal corticosteroids require 12 hours to several days for maximal efficacy, so patients must be counseled to use them regularly rather than as-needed 5