What are the key clinical features and diagnosis of chronic allergic rhinitis?

Key Clinical Features and Diagnosis of Chronic Allergic Rhinitis

Definition and Epidemiology

Allergic rhinitis is an immunoglobulin E (IgE)-mediated inflammatory disorder affecting the nasal mucosa, triggered by exposure to allergens in sensitized individuals. It affects approximately 15% of the US population (around 50 million individuals) and is the fifth most common chronic disease in the United States 1, 2.

Clinical Features

The key clinical features of chronic allergic rhinitis include nasal congestion, rhinorrhea, sneezing, and itching of the eyes, nose, and throat, with rhinorrhea (90.38%) and nasal congestion (94.23%) being the most common symptoms. 1

Cardinal Symptoms

• Nasal symptoms:

  • Nasal congestion/obstruction
  • Rhinorrhea (clear nasal discharge)
  • Sneezing (often paroxysmal)
  • Nasal itching
  • Postnasal drainage

• Ocular symptoms:

  • Itchy eyes
  • Watery eye discharge
  • Conjunctival swelling

Physical Examination Findings

• Nasal findings:

  • Seasonal allergic rhinitis: Edematous and pale turbinates 1
  • Perennial allergic rhinitis: Erythematous and inflamed turbinates with serous secretions 1
  • Clear rhinorrhea
  • Swollen nasal turbinates

• Other findings:

  • "Allergic shiners" (dark circles under the eyes) 2
  • Conjunctival injection
  • "Allergic salute" (upward rubbing of the nose)
  • "Allergic crease" (horizontal line across the lower third of the nose)

Classification

Allergic rhinitis can be classified based on temporal patterns:

1. Intermittent allergic rhinitis: Symptoms occurring less than 4 consecutive days/week or less than 4 consecutive weeks/year 1

2. Persistent allergic rhinitis: Symptoms occurring more than 4 consecutive days/week and for more than 4 consecutive weeks/year 1

Alternatively, it can be classified based on allergen exposure patterns:

1. Seasonal allergic rhinitis: Triggered by seasonal allergens like pollens

   • More prominent symptoms of sneezing and runny nose 3

2. Perennial allergic rhinitis: Triggered by year-round allergens like dust mites, molds, and animal dander

   • More prominent symptoms of nasal obstruction 3

Diagnostic Approach

Clinical Diagnosis

Diagnosis is primarily clinical, based on:

• Characteristic history of allergic symptoms
• Temporal relationship with allergen exposure
• Family history of allergic conditions (increases risk) 2
• Physical examination findings

Diagnostic Testing

Testing is indicated when:

• Inadequate response to empiric treatment
• Uncertain diagnosis
• To guide initiation or titration of therapy 2

Testing Options:

1. Skin prick testing (SPT):

   • Preferred initial test
   • Rapid results (15-20 minutes)
   • High sensitivity and specificity
   • Tests for immediate hypersensitivity reactions

2. Serum specific IgE testing:

   • Alternative when skin testing is contraindicated
   • Not affected by antihistamine use
   • Results take longer to obtain
   • May be less sensitive than skin testing

Differential Diagnosis

Important to differentiate from:

• Nonallergic rhinitis (negative specific IgE tests) 1
• Infectious rhinitis
• Vasomotor rhinitis
• Rhinitis medicamentosa
• Chronic rhinosinusitis
• Anatomic abnormalities

Associated Conditions

Allergic rhinitis is frequently associated with:

• Asthma (approximately 10% of patients with allergic rhinitis will develop asthma) 2
• Atopic dermatitis/eczema
• Chronic or recurrent sinusitis
• Chronic cough
• Tension and migraine headaches 1
• Eustachian tube dysfunction

Common Pitfalls and Caveats

• Patients with allergic rhinitis often have symptoms after exposure to non-specific triggers (temperature changes, irritants), which can sometimes cause more severe symptoms than allergen exposure 3
• Non-specific nasal hyperreactivity can complicate the clinical picture 3
• Dust mite-proof mattress covers do not prevent allergic rhinitis in children two years and younger 2
• High-efficiency particulate air (HEPA) filters are not effective at decreasing allergy symptoms 2
• Prolonged use of nasal decongestants can lead to rebound congestion (rhinitis medicamentosa) 3