Definition
Rhinitis refers to inflammation of the nasal mucosa, characterized by symptoms such as nasal congestion, rhinorrhea (runny nose), sneezing, and itching. It can be classified into allergic, non-allergic, and infectious forms based on its cause.
Classification
1. Allergic Rhinitis (AR):
IgE-mediated hypersensitivity reaction to allergens.
Subtypes:
Seasonal Allergic Rhinitis (SAR): Triggered by pollen (hay fever).
Perennial Allergic Rhinitis (PAR): Triggered by year-round allergens like dust mites, mold, or pet dander.
Occupational Allergic Rhinitis: Triggered by allergens in the workplace.
2. Non-Allergic Rhinitis (NAR):
Inflammation without an allergic cause.
Subtypes include:
Vasomotor Rhinitis: Triggered by temperature changes, strong odors, or smoke.
Hormonal Rhinitis: Seen in pregnancy or hypothyroidism.
Drug-Induced Rhinitis: Caused by prolonged use of nasal decongestants (rhinitis medicamentosa).
Atrophic Rhinitis: Thinning of nasal mucosa, often with crusting.
3. Infectious Rhinitis:
Caused by viral, bacterial, or fungal infections.
4. Mixed Rhinitis:
Combination of allergic and non-allergic rhinitis.
Epidemiology
Allergic Rhinitis: Affects 10-30% of the global population.
More common in children and young adults; peak prevalence in late adolescence.
Higher prevalence in urban areas due to pollution and allergens.
Non-allergic rhinitis is more common in older adults.
Etiology
1. Allergic Rhinitis:
Caused by environmental allergens:
Pollen (trees, grasses, weeds)
Dust mites
Animal dander
Mold spores
Involves IgE-mediated immune response.
2. Non-Allergic Rhinitis:
Idiopathic triggers include:
Environmental irritants: smoke, pollution, strong odors
Hormonal changes (e.g., pregnancy)
Medications (e.g., overuse of nasal decongestants, beta-blockers, NSAIDs)
3. Infectious Rhinitis:
Viruses (e.g., rhinovirus, coronavirus, influenza, adenovirus).
Less commonly bacterial or fungal pathogens.
Risk Factors
1. Family history of allergic rhinitis or atopy.
2. Environmental exposure to allergens or irritants.
3. Asthma or eczema (allergic triad).
4. Occupational exposure to irritants or allergens.
5. Smoking and air pollution.
6. Hormonal changes (e.g., pregnancy, menopause).
7. Prolonged use of nasal decongestants.
Clinical Features
Allergic Rhinitis:
Nasal congestion.
Rhinorrhea (clear discharge).
Sneezing.
Nasal itching.
Postnasal drip.
Conjunctival symptoms: itchy, red eyes.
Pale, swollen nasal mucosa.
Allergic salute (habitual nose rubbing).
Non-Allergic Rhinitis:
Similar to allergic rhinitis but without itching or conjunctival symptoms.
Infectious Rhinitis:
Nasal congestion and rhinorrhea (may be thick and purulent).
Fever, malaise, and sore throat in viral infections.
Complications
1. Chronic sinusitis.
2. Otitis media (middle ear infection).
3. Nasal polyps.
4. Sleep disturbances (e.g., obstructive sleep apnea).
5. Decreased quality of life due to persistent symptoms.
Differential Diagnosis
1. Sinusitis: Presents with facial pain, pressure, and purulent discharge.
2. Nasal Polyps: Chronic nasal obstruction and anosmia (loss of smell).
3. Foreign Body (in children): Unilateral nasal obstruction with foul-smelling discharge.
4. Deviated Nasal Septum: Chronic nasal blockage.
5. Upper Respiratory Tract Infection: Acute onset with systemic symptoms like fever.
Treatments
1. Allergic Rhinitis:
Avoidance of allergens: Minimize exposure to known triggers.
Pharmacotherapy:
Intranasal corticosteroids (e.g., fluticasone, budesonide).
Oral antihistamines (e.g., cetirizine, loratadine).
Intranasal antihistamines (e.g., azelastine).
Leukotriene receptor antagonists (e.g., montelukast).
Decongestants (short-term use to avoid rhinitis medicamentosa).
Immunotherapy: Allergy shots or sublingual tablets for severe cases.
2. Non-Allergic Rhinitis:
Avoid triggers (smoke, irritants).
Nasal saline irrigation.
Intranasal corticosteroids or antihistamines.
Ipratropium nasal spray (for rhinorrhea).
3. Infectious Rhinitis:
Viral: Supportive care with saline sprays, hydration, and analgesics.
Bacterial: Antibiotics only if bacterial sinusitis is confirmed.
Prevention
1. Allergen avoidance:
Use air purifiers.
Encase bedding in allergen-proof covers.
Wash bedding and stuffed toys regularly.
Reduce mold and pet dander exposure.
2. Lifestyle measures:
Avoid smoking and exposure to irritants.
Maintain good hygiene to reduce infections.
3. Pharmacologic prophylaxis:
Pre-seasonal use of antihistamines for seasonal allergic rhinitis.
4. Immunotherapy: Effective in preventing progression of allergic rhinitis.
