Rhinitis
Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management
Definition
Rhinitis is the inflammation of the nasal mucosa, leading to symptoms such as nasal congestion, sneezing, rhinorrhoea, and nasal itching. It can be allergic, non allergic, or infective in origin.
Aetiology
- Allergic rhinitis: triggered by allergens such as pollen, dust mites, pet dander, and mould.
- Non allergic rhinitis: caused by irritants like smoke, strong odours, weather changes, or hormonal fluctuations.
- Infective rhinitis: viral (e.g., rhinovirus, influenza), bacterial, or fungal infections.
- Drug induced rhinitis: associated with prolonged use of decongestant nasal sprays (rhinitis medicamentosa) or certain medications (e.g., beta blockers, ACEi).
Pathophysiology
- In allergic rhinitis, exposure to allergens triggers an IgE-mediated immune response, leading to mast cell degranulation and histamine release.
- Non allergic rhinitis results from direct irritation of the nasal mucosa, causing neurogenic inflammation.
- Infective rhinitis leads to increased mucus production and local inflammation due to microbial invasion.
Risk Factors
- Personal or family history of atopy (e.g., asthma, eczema).
- Exposure to allergens or environmental pollutants.
- Smoking or passive smoke exposure.
- Frequent respiratory infections.
- Occupational exposure to irritants (e.g., chemicals, dust).
Signs and Symptoms
- Nasal congestion: leading to difficulty breathing through the nose.
- Sneezing: particularly in allergic rhinitis.
- Rhinorrhoea: clear nasal discharge in allergic/non-allergic rhinitis, purulent in infective rhinitis.
- Nasal itching: common in allergic rhinitis.
- Postnasal drip: sensation of mucus in the throat.
- Facial pressure or discomfort: may be present in some cases.
Investigations
- Clinical diagnosis: based on history and examination.
- Skin prick testing or specific IgE testing: to identify allergens in allergic rhinitis.
- Nasal endoscopy: if structural abnormalities or chronic rhinitis are suspected.
- Full blood count (FBC): eosinophilia may be present in allergic rhinitis.
- Nasal swabs: for microbial culture in suspected bacterial or fungal infections.
Management
1. Avoidance of Triggers:
- Avoid known allergens (e.g., pollen, pet dander, dust mites).
- Reduce exposure to irritants (e.g., smoke, strong odours).
2. Pharmacological Treatment:
- Intranasal corticosteroids: first line treatment for allergic and non-allergic rhinitis (e.g., fluticasone, mometasone).
- Antihistamines: for allergic rhinitis (e.g., loratadine, cetirizine).
- Intranasal antihistamines: azelastine for rapid symptom relief.
- Leukotriene receptor antagonists: for allergic rhinitis in combination with other therapies (e.g., montelukast).
- Saline nasal irrigation: helps clear allergens and mucus.
3. Immunotherapy:
- Subcutaneous or sublingual immunotherapy for persistent allergic rhinitis.
4. Surgical Management:
- Indicated for nasal polyps or deviated nasal septum contributing to symptoms.
5. Referral:
- ENT specialist: for chronic, treatment-resistant rhinitis.
- Allergy specialist: if immunotherapy is being considered.
- Respiratory specialist: if associated with uncontrolled asthma.