PART A. DIAGNOSIS KEY POINTS
CLINICAL DIAGNOSIS OF ASTHMA
It may be challenging to make a confident diagnosis of asthma in children 5 years and younger, because episodic respiratory symptoms such as wheezing and cough are also common in children without asthma, particularly in those 0–
2 years old,619,620 and it is not possible to routinely assess airflow limitation or bronchodilator responsiveness in this age group. A probability-based approach, based on the pattern of symptoms during and between viral respiratory
infections,621 may be helpful for discussion with parents/carers (Box 6-1 & 2). This allows individual decisions to be made about whether to give a trial of controller treatment. It is important to make decisions for each child individually, to avoid either over- or under-treatment.
Box 6-1. Probability of asthma diagnosis in children 5 years and younger
Symptoms suggestive of asthma in children 5 years and younger
As shown in Box 6-1 & 2 an asthma diagnosis in children 5 years and younger can often be based on:
• Symptom patterns (recurrent episodes of wheeze, cough, breathlessness (typically manifested by activity limitation), and nocturnal symptoms or awakenings)
• Presence of risk factors for development of asthma, such as family history of atopy, allergic sensitisation, allergy or asthma, or a personal history of food allergy or atopic dermatitis
• Therapeutic response to controller treatment.
• Exclusion of alternate diagnoses.
Box 6-1 is a schematic figure showing the estimated probability of an asthma diagnosis597,598 in children aged 5 years or younger who have viral-induced cough, wheeze or heavy breathing, based on the pattern of symptoms. Many young
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children wheeze with viral infections and deciding when a child should be given controller treatment may be difficult. The frequency and severity of wheezing episodes and the temporal pattern of symptoms (only with viral colds or also in response to other triggers) should be taken into account. Any controller treatment should be viewed as a treatment trial, with follow up scheduled after 2–3 months to review the response. Review is also important since the pattern of
symptoms tends to change over time in a large proportion of children.
A diagnosis of asthma in young children is therefore based largely on recurrent symptom patterns combined with a careful clinical assessment of family history and physical findings with careful consideration of the differential diagnostic possibilities. A positive family history of allergic disorders, or the presence of atopy or allergic sensitization provide additional predictive support, as early allergic sensitization increases the likelihood that a wheezing child will develop persistent asthma.610
Box 6-2. Features suggesting a diagnosis of asthma in children 5 years and younger
Feature Characteristics suggesting asthma
Cough Recurrent or persistent non-productive cough that may be worse at night or accompanied by some wheezing and breathing difficulties
Cough occurring with exercise, laughing, crying or exposure to tobacco smoke, particularly in the absence of an apparent respiratory infection
Wheezing Recurrent wheezing, including during sleep or with triggers such as activity, laughing, crying or exposure to tobacco smoke or air pollution
Difficult or heavy breathing or shortness of breath
Occurring with exercise, laughing, or crying
Reduced activity Not running, playing or laughing at the same intensity as other children; tires earlier during walks (wants to be carried)
Past or family history Other allergic disease (atopic dermatitis or allergic rhinitis, food allergy).
Asthma in first-degree relative(s) Therapeutic trial with low dose inhaled
corticosteroid (Box 6-5, p.143), and as-needed SABA
Clinical improvement during 2–3 months of controller treatment and worsening when treatment is stopped
Box 6-2A gives examples of questions that can be used to elucidate the features suggestive of an asthma diagnosis.
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Box 6-2A. Questions that can be used to elicit features suggestive of asthma
• Does your child have wheezing? Wheezing is a high pitched noise which comes from the chest and not the throat.
Use of a video questionnaire,622 or asking a parent to record an episode on a smartphone if available can help to confirm the presence of wheeze and differentiate from upper airway abnormalities
• Does your child wake up at night because of coughing, wheezing, or ‘difficult breathing’, ‘heavy breathing’, or
‘breathlessness?
• Does your child have to stop running, or play less hard, because of coughing, wheezing or ‘difficult breathing’,
‘heavy breathing’, or ‘shortness of breath’?
• Does your child cough, wheeze or get ‘difficult breathing’, ‘heavy breathing’, or ‘shortness of breath’ when laughing, crying, playing with animals, or when exposed to strong smells or smoke?
• Has your child ever had eczema, or been diagnosed with allergy to foods?
• Has anyone in your family had asthma, hay fever, food allergy, eczema, or any other disease with breathing problems?
Wheeze
Wheeze is the most common and specific symptom associated with asthma in children 5 years and younger. Wheezing occurs in several different patterns, but a wheeze that occurs recurrently, during sleep, or with triggers such as activity, laughing, or crying, is consistent with a diagnosis of asthma. Clinician confirmation is important, as parents may describe any noisy breathing as ‘wheezing’.623 Some cultures do not have a word for wheeze.
Wheezing may be interpreted differently based on:
• Who observes it (e.g. parent/carer versus the health care provider)
• The environmental context (e.g. developed countries versus areas with a high prevalence of parasites that involve the lung)
• The cultural context (e.g. the relative importance of certain symptoms can differ between cultures, as can the diagnosis and treatment of respiratory tract diseases in general).
Cough
Cough due to asthma is generally non-productive, recurrent and/or persistent, and is usually accompanied by wheezing episodes and breathing difficulties. Allergic rhinitis may be associated with cough in the absence of asthma. A nocturnal cough (when the child is asleep) or a cough that occurs with exercise, laughing or crying, in the absence of an apparent respiratory infection, supports a diagnosis of asthma. The common cold and other respiratory illnesses are also
associated with coughing. Prolonged cough in infancy, and cough without cold symptoms, are associated with later parent-reported physician-diagnosed asthma, independent of infant wheeze. Characteristics of cough in infancy may be early markers of asthma susceptibility, particularly among children with maternal asthma.624
Breathlessness
Parents may also use terms such as ‘difficult breathing’, ‘heavy breathing’, or ‘shortness of breath’. Breathlessness that occurs during exercise and is recurrent increases the likelihood of the diagnosis of asthma. In infants and toddlers, crying and laughing are equivalent to exercise in older children.
Activity and social behavior
Physical activity is an important trigger of asthma symptoms in young children. Young children with poorly controlled asthma often abstain from strenuous play or exercise to avoid symptoms, but many parents are unaware of such changes in their children’s lifestyle. Engaging in play is important for a child’s normal social and physical development.
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For this reason, careful review of the child’s daily activities, including their willingness to walk and play, is important when assessing a potential asthma diagnosis in a young child. Parents may report irritability, tiredness and mood changes in their child as the main problems when asthma is not well controlled.