Paediatrics: Asthma

Asthma

Asthma is a disease of chronic airway inflammation, bronchial hyper-reactivity, and reversible airway obstruction. It affects 10% of the population and can develop at any age, but typically half of the paediatric cases present before the age of 10yrs. There is often a family history of asthma or atopic disease.

Diagnosis

History

• Cough after exercise or sometimes in the early morning, disturbing sleep.
• Shortness of breath.
• Limitation in exercise performance.

Examination

In the child with chronic problems consistent findings include:

• Barrel-shaped chest.
• Hyperinflation.
• Wheeze and prolonged expiration.

Chest X-ray

Not needed if there has been recent imaging. It may show:

• Hyperinflation.
• Flattened hemi-diaphragms.
• Peribronchial cuffing.
• Atelectasis.

Spirometry

• Peak expiratory flow rate (PEFR) <80% predicted for height.
• FEV₁/FVC <80% predicted.
• Concave scooped shape in the flow-volume curve.
• Bronchodilator response to β-agonist therapy (i.e. 15% increase in FEV₁or PEFR).

Medication

The main medications used for maintenance are bronchodilators, which give short-term relief of symptoms, and prophylactic therapy, which reduces chronic inflammation and bronchial hyperreactivity. In the out-patient clinic our aim is to titrate these treatments so that the child can function normally, yet still avoid any detrimental effect on growth and development.

Bronchodilators

• Short-acting β2-agonists: salbutamol, terbutaline.
• Long-acting β2-agonists: salmeterol, formoterol.

Short-acting anticholinergic: ipratropium bromide.

Chronic treatment of inflammation and hyperreactivity

• Inhaled steroids: budesonide, beclometasone, fluticasone.
• Oral steroids: prednisolone.
• Sodium cromoglicate: rarely used.
• Methylxanthines: theophylline.
• Leukotriene inhibitors: montelukast and zafirlukast may reduce the amount of steroid therapy that is needed to control symptoms.
• Combination inhalers containing inhaled steroids and long-acting B₂-agonists.

Side-effects of chronic treatment

Steroids

When long-term oral steroids or high-dose inhaled steroids are used, special attention will need to be given to unwanted effects including:

• Impaired growth: can affect growth in height, but also ask about the frequency of haircuts, or changing shoe size, as these are early indicators of poor growth.
• Adrenal suppression.
• Oral candidiasis.
• Altered bone metabolism.

Theophylline

Now rarely used in children, but you should be aware that there are a number of problems related to toxic blood levels, including:

• Vomiting
• Sleep disturbance or increased sleeping.
• Headaches.
• Poor concentration and deterioration of performance at school.

Arrhythmias.