A persistent wheeze or breathlessness in young children under seven can often result in a diagnosis of asthma. In this excerpt of their article from the October 2012 edition of Journal of Family Health Care magazine, Dr Siba Paul and his co-authors Dr O'Keefe, Dr Sanjeevaiah and Dr Brettle explain that there are many differential diagnoses which should also be considered. To read the article in full click here to subscribe.
The World Health Organization defines asthma as "a disease characterised by recurrent attacks of breathlessness and wheezing which vary in frequency and severity from person to person". It is estimated that more than 1.1 million children in the UK currently receive asthma treatment, with boys more affected than girls before puberty.
The cause of asthma remains poorly understood, although it is more common in children with a personal or family history of atopy. Currently there are no tests for asthma and so diagnosis is clinical, largely dependent on parental history of symptoms such as cough, wheeze and shortness of breath. It is important that the history is carefully elicited by the clinician as studies have shown that a significant number of parents may mistakenly interpret rattly or noisy breathing as wheezing.
What is asthma?
Although there is no universally agreed definition for asthma, most definitions emphasise the presence of symptoms (more than one of wheeze, breathlessness, chest tightness and cough) and the presence of variable airflow obstruction. Given that it is not possible to routinely assess airway function in children under five years, the diagnosis is therefore based primarily on symptoms, in particular the presence of cough and wheeze.
The diagnosis of asthma is further hampered in young children because these two symptoms are common in children who do not have asthma, especially those less than three years of age. Wheeze is also very common, with up to 50% of children having at least one episode of wheezing before reaching school age.
It has been recognised for many years that two-thirds of children with cough and wheeze in the first few years of life subsequently mature out of these symptoms, whilst those for whom cough and wheeze persist or subsequently develop, grow into the more homogeneous group with what we can more confidently label "atopic asthma". Most children (80%) who develop asthma are diagnosed before the age of seven.
Differential diagnosis of asthma in children
In addition to focusing on the symptoms of cough, wheeze and shortness of breath, and the clinical features that either increase or decrease the likelihood of asthma referred to above, care should be taken to consider and exclude the other diagnostic possibilities. Specific investigations such as chest x-ray (to exclude structural abnormalities or chronic infections) and tests to exclude cystic fibrosis, primary ciliary dyskinesia or immunodeficiency may be considered and are more likely to be found in children with systemic illness, faltering growth and severe or persistent respiratory symptoms. A moist cough with purulent sputum is not a feature of asthma.
Bronchiolitis is a very common respiratory illness which may affect up to 20-30% of infants in the first six months, with admission to hospital for those with most severe disease. While the illness itself is self-limiting and usually requires only supportive management, it may lead to increased airway reactivity over subsequent months, which may in turn be associated with symptoms of cough and wheeze.
Foreign body inhalation
This is characterised by a sudden onset of wheezy symptoms in a previously healthy young child without a preceding respiratory illness. This is most commonly seen in children younger than three years of age and can lead to accidental deaths. It is estimated that in the USA almost 600 children aged less than 15 years of age die each year due to aspiration of foreign bodies. The actual ingestion may often go unnoticed and it is important to have a high index of suspicion, especially in younger children and those whose symptoms will not respond to standard asthma therapies. These children need referral to specialist services urgently for removal of the foreign body and to prevent development of chronic pulmonary pathologic conditions - wheeze being a commonly noted symptom
Management of asthma in children
The important steps in the management of childhood asthma include an explanation about the diagnosis to the child and the family, consideration of the need for pharmacological therapy and a discussion about the most suitable delivery device to be employed. It is recommended that a spacer device is used in all ages for better and controlled delivery of the drugs. It is helpful to explain to parents that spacer usage improves drug delivery, minimises systemic drug side effects and reduces local side effects, such as throat irritation, hoarse voice and oral candidiasis. Parents in particular need to understand the difference between preventer and reliever medications as well as being given clear advice on what to do in the event of an exacerbation.
Role of the community practitioners
Childhood asthma is a chronic condition in which community practitioners play a vital role in supporting these children both in the home environment and within nurse-led asthma clinics. The following strategies may be helpful in supporting children with asthma in the community:
1) Refer children with wheezy symptoms to specialist services or nurse-led asthma clinics early for a proper diagnosis.
2) Review the newborn blood spot screening in children with chronic respiratory symptoms to make sure a diagnosis of cystic fibrosis has not been missed. This is especially relevant in children who may have moved from another area of the country.
3) Make sure a regular supply of inhalers is available and the child is taken to the clinic for review.
4) Provide explanation and information leaflets about non-asthma conditions.
5) Re-emphasise the need for using a spacer device for better drug delivery, especially in young children who need inhalers.
Childhood asthma is a chronic condition which can have long-term health implications. The community practitioners should aim to recognise the signs of evolving asthma and refer to the specialist clinic for a proper diagnosis. A focused history and physical examination is necessary to establish the diagnosis.
Once a diagnosis is made and inhalers are considered necessary, a spacer should always be used to improve drug delivery. BTS/SIGN guidelines on asthma should guide the management of a child with asthma. Education and offering support to parents are both necessary to improve compliance and successful management of childhood asthma.