Asthma Children

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management

Definition

Asthma in children is a chronic inflammatory disease of the airways characterised by variable airflow obstruction, bronchial hyperresponsiveness, and symptoms such as wheezing, coughing, and breathlessness.

Aetiology

  • Genetic predisposition.
  • Environmental triggers (e.g., allergens, pollution, cold air).
  • Respiratory infections.
  • Exposure to tobacco smoke.

Pathophysiology

  • Chronic airway inflammation leads to bronchoconstriction and airway hyperreactivity.
  • Excess mucus production and airway remodelling contribute to obstruction.
  • Symptoms fluctuate based on exposure to triggers.

Risk Factors

  • Family history of asthma or atopy.
  • Personal history of allergic conditions (e.g., eczema, allergic rhinitis).
  • Exposure to allergens (dust mites, pet dander, pollen).
  • Viral respiratory infections.
  • Low birth weight and prematurity.

Signs and Symptoms

  • Wheezing.
  • Persistent or recurrent cough (worse at night or with exertion).
  • Breathlessness, especially with triggers.
  • Chest tightness.
  • Reduced exercise tolerance.

Investigations

  • Peak expiratory flow rate (PEFR): monitors airway obstruction.
  • Spirometry: confirms obstructive lung disease in children >5 years.
  • Bronchodilator reversibility testing: assesses response to beta-agonists.
  • Fractional exhaled nitric oxide (FeNO): measures airway inflammation.
  • Skin prick or IgE testing: identifies allergic triggers.

Management

Stepwise treatment escalation based on symptom control (following SEL guidelines).

1. Under 5 Years:

  • Step 1: Very low dose inhaled corticosteroid (ICS) - Clenil 50 pMDI (2 puffs BD).
  • Step 2: Add leukotriene receptor antagonist (LRTA) - trial for 4-8 weeks (Montelukast 4mg in the evening).
  • Step 3: Low-dose ICS - Clenil 100 pMDI (2 puffs BD).
  • Referral: If symptoms persist despite step 3, seek specialist advice.

2. 6-11 Years:

  • Step 1: Very low dose ICS - Clenil 50 pMDI or Flixotide 50 pMDI (2 puffs BD).
  • Step 2: Low dose ICS - Clenil 100 pMDI or Flixotide 50 pMDI (2 puffs BD).
  • Step 3: Low dose ICS + LABA (Seretide Evohaler 50/25, 2 puffs BD).
  • Step 4: Low dose ICS + LABA +/- LRTA (especially if allergic rhinitis).
  • Referral: If not controlled at step 4, seek specialist advice.

3. 12-17 Years:

  • Choice between propellant (pMDI) and non propellant (DPI/SMI) inhalers.
  • Consider SABA-Free pathway using MART (ICS/LABA) if appropriate.
  • Step 1: Low dose ICS + bronchodilator.
  • Step 2: Moderate dose ICS/LABA (DPI or pMDI options available).
  • Step 3: High dose ICS/LABA - seek advice before stepping up.
  • Referral: If control remains poor despite escalation, refer to respiratory specialist.

4. Acute Asthma Management:

  • Mild to moderate: SABA via spacer (10 puffs if needed), consider oral prednisolone.
  • Severe: Immediate nebulised SABA + ipratropium, oral steroids.
  • Life-threatening: Urgent hospital admission, oxygen therapy, IV salbutamol or aminophylline.

5. Referral:

  • Respiratory specialist: if uncontrolled despite stepwise escalation.
  • Paediatrics: for severe or life-threatening asthma.
  • Allergy services: if allergic asthma suspected.
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