Paediatric asthma: a common condition
Dr Ranjan Suri MBChB MRCPCH MD is a paediatric respiratory consultant at Bupa Cromwell Hospital and Great Ormond Street Hospital.
Asthma is a common disease, affecting 15 percent of children in the UK. Typically the child with asthma will have episodes of wheeze, cough and difficulty in breathing. These symptoms tend to be frequent and recurrent, are classically worse at night and in the early morning. There are common triggers for these symptoms including viral upper respiratory tract infections, exercise, contact with pets, cold or damp air. There is often a personal history of atopic disorder and a family history of atopy. When the child is having an exacerbation, there is typically a widespread wheeze heard on auscultation and the symptoms improve in response to standard asthma therapy.
Making the diagnosis
A diagnosis can usually be made on history and examination alone. One of the key features that consistently points to the diagnosis of asthma is the presence of wheeze. However, studies have shown that parents mistakenly call a variety of different airway noises (such as whistling or stridor) as wheeze. Therefore, it is important to be certain exactly what they mean
Cough is a common complaint in childhood. If the predominant symptom is cough, and the child has never been heard to wheeze, be cautious about making a diagnosis of asthma too early on. Cough variant asthma does exist but is rare.
Having established whether the child truly wheezes, the next step is to identify the pattern and severity of the symptoms. Specific triggers may include dust, exercise, laughing or crying, changes in weather, exposure to pets, as well as perfumes, cigarette smoke and environmental pollution. It is important to determine whether the child has symptoms solely at the time of a viral upper respiratory tract infection (virus induced or associated wheeze), or if there are additional symptoms in between infections. Episodic viral wheeze is common, particularly in preschool children. Some young children with atopic asthma start with recurrent viral induced wheeze before more persistent features develop. However, most children with pure episodic viral induced wheeze tend to outgrow their symptoms as they get older.
Alternative diagnoses of paediatric asthma
There are many conditions than can mimic asthma in children. Specific questions should be asked in the history (Table 1) and unusual clinical signs elicited on examination (Table 2) to exclude an underlying serious disorder. Alternative diagnoses include: structural abnormalities (eg bronchomalacia or stenosis), gastro-oesophageal reflux, a laryngeal problem, post-bronchiolitic wheeze, bronchiectasis (eg cystic fibrosis or primary ciliary dyskinesia), bronchopulmonary dysplasia, immunodeficiency, aspiration of foreign body, obliterative bronchiolitis, and congestive cardiac failure.
Management of paediatric asthma
All children with asthma should have a written, individualised asthma management plan on acute management, guidance on daily treatment and when to call the emergency services. This must also include avoidance of airborne allergens and irritant triggers.
In children with atopic asthma, the long-term management is clearly defined by the British Thoracic Society/Scottish Intercollegiate Guidelines Network (BTS/SIGN) guideline (see Further Reading). There are variations depending on the age of the child. The management follows a stepwise approach until control is achieved. Patients are then maintained on the lowest level of treatment that still achieves control, with regular attempts to reduce the level of treatment once control is achieved.
The introduction of inhaled steroids has enhanced the management of chronic childhood asthma. Considerable benefit is seen with low to moderate doses (beclometasone up to 400 microgram/day or fluticasone up to 200 microgram/day). Beyond this, however, the dose-response curve is relatively flat in most children. Although side effects are unlikely at doses of 400 microgram/day of beclometasone equivalent, they become apparent at the higher doses.
One method of achieving better asthma control without increasing the dose of inhaled steroids is the addition of a long acting β2 agonist and/or a leukotriene receptor antagonist. Recently, leukotriene receptor antagonists have shown effectiveness in the management of viral induced wheeze, with one study showing a significant reduction in the rate of exacerbation and oral corticosteroid use.
Drug delivery for paediatric asthma patients
To optimise inhaled drug delivery for children with asthma, the correct inhaler device must be prescribed (Figures 1 and 2). NICE has recently published guidance on recommended inhaler devices for children (see Further Reading). Teaching both the patient and family correct technique for use of the inhaler can be handled by either the specialist or the paediatric nurses and is another important aspect of optimising drug delivery. At each clinic consultation, adherence to therapy as well as a review of inhaler technique must be assessed.
When to refer to a respiratory paediatrician
- If the GP is unfamiliar with treatments that are added on to inhaled corticosteroids; if 400 microgram/day of beclometasone or equivalent is not achieving control, then referral is advisable.
- Patient has reached step 4 of BTS/SIGN guideline.
- Parental concern or need for reassurance.
- Recurrent admission to hospital with acute asthma.
- Severe acute asthma, such as needing intravenous treatments or intensive care.
- Features that suggest another diagnosis or if the diagnosis is in doubt (Tables 1 and 2).