Rhinitis Overview and Classification

Rhinitis Definition

• Rhinitis is inflammation of the nasal lining, characterized by two or more nasal symptoms: runny nose, congestion, itching and sneezing.

Rhinitis Classification

• Rhinitis can be classified into two main subtypes: infectious rhinitis and non-infectious rhinitis.

Infectious Rhinitis

• Acute Rhinitis: A common, short-term inflammation of the nasal lining caused by a virus, usually lasting less than 10 days.
• Chronic Rhinosinusitis: A long-term inflammation of the nasal lining and sinuses caused by viruses, bacteria, and fungi.
  • Chronic Nonspecific Rhinosinusitis: This is a general type of chronic rhinosinusitis that cannot be linked to specific causes.
  • Chronic Specific Rhinosinusitis: This type is caused by specific organisms.

Non-Infectious Rhinitis

• Allergic Rhinitis: An IgE-mediated allergic reaction to allergens that triggers nasal symptoms.
• Non-Allergic Rhinitis: A group of conditions that cause nasal symptoms, but are not caused by allergies.
  • Idiopathic (Vasomotor) Rhinitis: This is characterized by nasal obstruction and clear drainage often caused by temperature changes, exposure to odors, chemicals, or alcohol.
  • Occupational Rhinitis: Caused by exposure to allergens in the workplace, such as dust, fumes, and chemicals.
  • Hormonal Rhinitis: Often associated with pregnancy due to increased estrogen levels, leading to increased fluid retention (edema) in the nasal lining.
  • Drug-Induced Rhinitis: Rhinitis triggered by medications, including aspirin, NSAIDs, methyledopa, ACE inhibitors, beta blockers, and oral contraceptives.
  • Rhinitis Medicamentosa: Rebound rhinitis caused by prolonged use of topical nasal decongestants, resulting in worsening symptoms.
  • Non-Allergic Rhinitis with Eosinophilia (NARES): A newly described syndrome characterized by nasal symptoms and an increased eosinophil count, but not allergic to inhalant allergens, and the cause is unknown.

Allergic Rhinitis Pathophysiology

• Allergic rhinitis is a type 1 hypersensitivity reaction.
• IgE binds to allergens and mast cells, triggering the release of mediators (histamine, prostaglandins, leukotrienes), resulting in blood vessel dilation, increased fluid leakage, leading to itching, sneezing and mucus secretion, and inflammation of the nasal lining.

Allergic Rhinitis Clinical Presentation

• Seasonal Allergic Rhinitis (Hay Fever): Triggered by seasonal allergens, such as pollen.
• Perennial Allergic Rhinitis (Atopic Rhinitis): Caused by allergens present year-round, such as dust mites.
• Allergic rhinitis symptoms typically include sneezing, runny nose, nasal congestion and itching, along with congestion, hyperreactivity, and impairment of the sense of smell.
• Eye symptoms: Allergic rhinitis can cause eye irritation and symptoms, such as tearing and burning sensations.

Allergic Rhinitis Etiology

• Underlying Causes:
  • Genetic Factors: Familial predispositions to allergies.
  • Environmental Factors:
    • Exposure to Allergens: Dust, pollens, feathers, fungal spores, house dust mites.
    • Air Pollution:
    • Occupational Exposure: Flour, wood dust, latex, tobacco, detergents, and bleach.
    • Some Foods: Preservatives, histamine-rich foods, such as certain cheeses and wines.
    • Medications: Penicillin, aspirin, antihypertensives, beta-blockers, and ACE inhibitors.

Allergic Rhinitis Diagnosis

• Diagnosis is based on clinical presentation and confirmed by laboratory tests.
• Nasal Cytology: Shows increased eosinophil count in nasal secretions and mucosa.
• Skin Prick Test (SPT): A confirmatory test where different allergens are introduced to the skin.
• Blood Test: Shows allergen-specific IgE levels through an ELISA (Enzyme-Linked Immunosorbent Assay) or RAST (Radioallergosorbent Test).
• Nasal Swab: For bacterial and viral culture.
• Nasal Allergen Challenge: A controlled exposure to an allergen.

Allergic Rhinitis Treatment

• Prevention:
  • Allergen Identification and Avoidance: Identifying and avoiding known allergens is the first step.
  • Patient Education: Understanding the triggers and management strategies.
• Pharmacologic Therapy:
  • Topical Corticosteroids: Nasal sprays, such as mometasone, beclomethasone, budesonide, and fluticasone propionate, are highly effective.
  • Antihistamines: Block histamine receptors, reducing symptoms, such as sneezing, runny nose and itching.
  • Decongestants: Short-term use, for nasal congestion Relief.
  • Leukotriene Modifiers: Block the actions of leukotrienes, reducing inflammation and symptoms.
• Immunotherapy:
  • Allergen Immunotherapy (AIT): Repeatedly administered injections of small doses of allergens to desensitize the immune system.

Non-Infectious Non-Allergic Rhinitis (NIANR)

• This group includes rhinitis conditions that are not related to allergies.
• Diagnosis: Clinical history and ruling out other causes.
• Treatment:
  • Avoidance: Environmental and occupational. & Use a mask if necessary.
  • Drug Discontinuation: If drug-induced rhinitis, stop the offending medication.
  • Pharmacologic Therapy:
    • Topical Intranasal Anticholinergics (Ipratropium Bromide), primarily for rhinorrhea.
    • Topical Intranasal Steroids: Used for both allergic and some non-allergic forms.
    • Alpha-Adrenergic Agents: Short-term use for congestion relief.
    • Saline Irrigation: Helps to prevent crust formation and nasal congestion
    • Intranasal Antihistamine Sprays: Tried for vasomotor rhinitis but effectiveness is questionable.
  • Surgery:
    • Septoplasty: Correction of structural abnormalities of the nasal septum.
    • Turbinate Surgery: To reduce the size of the inferior turbinates, often used to treat NIANR.