Preschool Wheeze

Preschool wheeze is recurrent wheeze in children aged 1 to 5 years, comprising episodic viral wheeze and multiple-trigger wheeze, as the umbrella term for early childhood wheezing illness.

• About a third of children wheeze in the first 3 years. Phenotypes differ in cause and prognosis.
• Episodic viral wheeze: only with colds and well between episodes.
• Multiple-trigger wheeze: wheeze with colds and also with exercise, allergens, smoke, cold air or laughing, with interval symptoms.
• Risk factors for persistence into asthma include parental asthma, eczema, allergic rhinitis, food allergy, aeroallergen sensitisation, eosinophilia and exposure to smoke.
• Clinical risk scores (the asthma predictive index) estimate chance of school-age asthma.

Pattern differs by phenotype.

• Episodic viral wheeze: wheeze and breathlessness for days with each cold, with no symptoms in between.
• Multiple-trigger wheeze: cough and wheeze at night, on waking, with exercise, laughing or allergen exposure, in addition to colds.
• Eczema, allergic rhinitis, and family history suggest atopy.
• Examination between episodes may be normal, or show persistent wheeze or hyperinflation.
• Differential diagnosis: asthma, bronchiolitis, foreign body, gastro-oesophageal reflux, cystic fibrosis, primary ciliary dyskinesia, tracheobronchomalacia, congenital heart disease, vascular ring, immunodeficiency and tuberculosis.
• Complications: hospital admissions, sleep disturbance, school absence, poor growth with severe disease, and progression to asthma.

Diagnosis is clinical, with identification of phenotype.

• Detailed history of triggers, timing, atopy, smoking exposure, and response to treatment.
• Examination between attacks, growth, and chest shape.
• Investigation if atypical: chest X-ray, sweat chloride, immunoglobulins, allergy tests (skin prick or specific IgE), full blood count (eosinophils), pH monitoring or swallow assessment, and bronchoscopy.
• Features suggesting an alternative cause: wheeze from birth, persistent wet cough, failure to thrive, focal signs, stridor, clubbing, cardiac murmur, and poor response to treatment.
• Treatment given for a defined period, with review of the response, is a useful diagnostic step.

Treat acute episodes and consider a time-limited course of preventer therapy.

• Supportive: avoid tobacco smoke and triggers, treat allergic rhinitis and eczema, keep immunisation up to date including influenza and pneumococcal vaccines.
• Pharmacological, acute: salbutamol 2 to 10 puffs by spacer, with oral prednisolone 1 to 2 mg/kg for 3 days for moderate to severe attacks.
• Episodic viral wheeze, frequent or severe: intermittent inhaled corticosteroid at onset of colds (for example beclometasone 100 micrograms twice daily for 7 to 10 days) or montelukast 4 mg nightly for 2 to 5 years.
• Multiple-trigger wheeze: daily inhaled corticosteroid (beclometasone 100 micrograms twice daily or budesonide 200 micrograms twice daily) for 4 to 8 weeks as a time-limited course. Stop if no benefit, and restart if symptoms recur. Add montelukast 4 mg nightly if not controlled.
• Check inhaler technique, use a spacer with a mask under 3 years, and give written action plan.
• Procedures: none routine; bronchoscopy for persistent unexplained wheeze.
• Special groups: children with severe or persistent symptoms despite treatment need specialist assessment.
• Red flags: wheeze from birth, persistent wet cough, failure to thrive, stridor, unilateral signs, hypoxia, and poor response to bronchodilators and steroids.
• Follow-up: review at 4 to 8 weeks after starting treatment and every 3 to 6 months. Reassess diagnosis at age 5 to 6 years, when spirometry becomes possible.