Paediatrics: Asthma

Asthma

Asthma is a disease of chronic airway inflammation, bronchial hyper-reac-tivity, and reversible airway obstruction. It affects 10% of the population and can develop at any age, but typically half of the paediatric cases pre-sent 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 flow volume curve.

·  Bronchodilator response to β-agonist therapy (i.e. 15% increase in FEV₁ or 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, spe-cial attention will need to be given to unwanted effects including:

·Impaired growth: can affect growth in height, but also ask about frequency of hair-cuts, 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.