Asthma Management Handbook

Making a provisional diagnosis in children

Recommendations

A provisional diagnosis of asthma can be made if the child has (all of):

  • wheezing accompanied by breathing difficulty or cough
  • other features that increase the probability of asthma such as a history of allergic rhinitis, atopic dermatitis or a strong family history of asthma and allergies
  • no signs or symptoms that suggest a serious alternative diagnosis
  • clinically important response to bronchodilator demonstrated on spirometry performed before and after short-acting beta2 agonist (if child is able to perform spirometry).

Notes

If reliable equipment and appropriately trained staff are available, spirometry can be performed in primary care. If not, refer to an appropriate provider such as an accredited respiratory function laboratory.

Most children aged 6 and older can perform spirometry reliably.

Airflow limitation is defined as reversible (i.e. bronchodilator response is clinically important) if FEV1 increases by ≥12%.

If spirometry does not demonstrate a clinically important response to bronchodilator, the test can be repeated when the child has symptoms.

Table. Findings that increase or decrease the probability of asthma in children

Asthma more likely

Asthma less likely

More than one of:

  • wheeze
  • difficulty breathing
  • feeling of tightness in the chest
  • cough

Any of:

  • symptoms only occur when child has a cold, but not between colds
  • isolated cough in the absence of wheeze or difficulty breathing
  • history of moist cough
  • dizziness, light-headedness or peripheral tingling
  • repeatedly normal physical examination of chest when symptomatic
  • normal spirometry when symptomatic (children old enough to perform spirometry)
  • no response to a trial of asthma treatment
  • clinical features that suggest an alternative diagnosis

AND

Any of:

  • symptoms recur frequently
  • symptoms worse at night and in the early morning
  • symptoms triggered by exercise, exposure to pets, cold air, damp air, emotions, laughing
  • symptoms occur when child doesn’t have a cold
  • history of allergies (e.g. allergic rhinitis, atopic dermatitis)
  • family history of allergies
  • family history of asthma
  • widespread wheeze heard on auscultation
  • symptoms respond to treatment trial of reliever, with or without a preventer
  • lung function measured by spirometry increases in response to rapid-acting bronchodilator
  • lung function measured by spirometry increases in response to a treatment trial with inhaled corticosteroid (where indicated)

Sources

British Thoracic Society (BTS), Scottish Intercollegiate Guidelines Network (SIGN). British Guideline on the management of Asthma. A national clinical guideline. BTS/SIGN, Edinburgh, 2012. Available from: https://www.brit-thoracic.org.uk/guidelines-and-quality-standards/asthma-guideline

Respiratory Expert Group, Therapeutic Guidelines Limited. Therapeutic Guidelines: Respiratory, Version 4. Therapeutic Guidelines Limited, Melbourne, 2009.

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Table. Conditions that can be confused with asthma in children

Conditions characterised by cough

Pertussis (whooping cough)

Cystic fibrosis

Airway abnormalities (e.g. tracheomalacia, bronchomalacia)

Protracted bacterial bronchitis in young children

Habit-cough syndrome

Conditions characterised by wheezing

Upper airway dysfunction

Inhaled foreign body causing partial airway obstruction

Tracheomalacia

Conditions characterised by difficulty breathing

Hyperventilation

Anxiety

Breathlessness on exertion due to poor cardiopulmonary fitness

Source

Weinberger M, Abu-Hasan M. Pseudo-asthma: when cough, wheezing, and dyspnea are not asthma. Pediatrics 2007; 120: 855-64. Available from: http://pediatrics.aappublications.org/content/120/4/855.full

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Table. Findings that require investigations in children

Finding

Notes

Persistent cough that is not associated with wheeze/breathlessness or systemic disease

 Unlikely to be due to asthma

Onset of signs from birth or very early in life

Suggests cystic fibrosis, chronic lung disease of prematurity, primary ciliary dyskinesia, bronchopulmonary dysplasia, congenital abnormality

Family history of unusual chest disease

Should be enquired about before attributing all the signs and symptoms to asthma

Severe upper respiratory tract disease (e.g. severe rhinitis, enlarged tonsils and adenoids or nasal polyps)

Specialist assessment should be considered

Crepitations on chest auscultation that do not clear on coughing

Suggest a serious lower respiratory tract condition such as pneumonia, atelectasis, bronchiectasis

Unilateral wheeze

Suggests inhaled foreign body

Systemic symptoms (e.g. fever, weight loss, failure to thrive)

Suggest an alternative systemic disorder

Feeding difficulties, including choking or vomiting

Suggests aspiration – specialist assessment should be considered

Inspiratory upper airway noises (e.g. stridor, snoring)

Acute stridor suggests tracheobronchitis (croup)

Persistent voice abnormality

Suggests upper airway disorder

Finger clubbing

Suggests cystic fibrosis, bronchiectasis

Chronic (>4 weeks) wet or productive cough

Suggests cystic fibrosis, bronchiectasis, chronic bronchitis, recurrent aspiration, immune abnormality, ciliary dyskinesia

Focal (localised) lung signs

Suggests pneumonia

Nasal polyps in child under 5 years old

Suggests cystic fibrosis

Severe chest deformity

Harrison’s Sulcus and Pectus Carinatum can be due to uncontrolled asthma, but severe deformity suggests an alternative diagnosis

Obvious breathing difficulty, especially at rest or at night

Specialist assessment should be considered

Recurrent pneumonia

Specialist assessment should be considered

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How this recommendation was developed

Consensus

Based on clinical experience and expert opinion (informed by evidence, where available).

Make an initial assessment of the pattern of asthma (infrequent intermittent, frequent intermittent, or persistent).

Table. Definitions of asthma patterns in children aged 0–5 years not taking regular preventer

Category

Pattern and intensity of symptoms (when not taking regular treatment)

Infrequent intermittent asthma

Symptom-free for at least 6 weeks at a time (flare-ups up to once every 6 weeks on average but no symptoms between flare-ups)

Frequent intermittent asthma

Flare-ups more than once every 6 weeks on average but no symptoms between flare-ups

Persistent asthma

Mild

At least one of:

  • Daytime symptoms more than once per week but not every day
  • Night-time symptoms more than twice per month but not every week

Moderate

Any of:

  • Daytime symptoms daily
  • Night-time symptoms more than once per week
  • Symptoms sometimes restrict activity or sleep

Severe

Any of:

  • Daytime symptoms continual
  • Night-time symptoms frequent
  • Flare-ups frequent
  • Symptoms frequently restrict activity or sleep

† Symptoms between flare-ups. A flare-up is defined as a period of worsening asthma symptoms, from mild (e.g. symptoms that are just outside the normal range of variation for the child, documented when well) to severe (e.g. events that require urgent action by parents and health professionals to prevent a serious outcome such as hospitalisation or death from asthma).

Note: Use this table when the diagnosis of asthma can be made with reasonable confidence (e.g. a child with wheezing accompanied by persistent cough or breathing difficulty, no signs or symptoms that suggest a potentially serious alternative diagnosis, and the presence of other factors that increase the probability of asthma such as family history of allergies or asthma).

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Table. Definitions of asthma patterns in children aged 6 years and over not taking regular preventer

Category

Pattern and intensity of symptoms (when not taking regular treatment)

Infrequent intermittent asthma †

Symptom-free for at least 6 weeks at a time (flare-ups up to once every 6 weeks on average but no symptoms between flare-ups)

Frequent intermittent asthma

Flare-ups more than once every 6 weeks on average but no symptoms between flare-ups

Persistent asthma

Mild

FEV1 ≥80% predicted and at least one of:

  • Daytime symptoms more than once per week but not every day
  • Night-time symptoms more than twice per month but not every week

Moderate

Any of:

  • FEV1 <80% predicted
  • Daytime symptoms daily
  • Night-time symptoms more than once per week
  • Symptoms sometimes restrict activity or sleep

Severe

Any of:

  • FEV1 ≤60% predicted
  • Daytime symptoms‡ continual
  • Night-time symptoms frequent
  • Flare-ups frequent
  • Symptoms frequently restrict activity or sleep

† It may not be appropriate to make the diagnosis of asthma in children aged 6 or older who wheeze only during upper respiratory tract infections. These children can be considered to have episodic (viral) wheeze.

‡ Symptoms between flare-ups. A flare-up is defined as a period of worsening asthma symptoms, from mild (e.g. symptoms that are just outside the normal range of variation for the child, documented when well) to severe (e.g. events that require urgent action by parents and health professionals to prevent a serious outcome such as hospitalisation or death from asthma).

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How this recommendation was developed

Consensus

Based on clinical experience and expert opinion (informed by evidence, where available).

More information

Spirometry in children

Measuring lung function in young children is difficult and requires techniques that are not widely available.1 Generally, spirometry cannot be performed to acceptable standards in children younger than 4–5 years.2

Some older children cannot perform spirometry either. However, children who are unable to perform spirometry satisfactorily on their first visit are often able to perform the test correctly at the next visit.2

Spirometry is poor at discriminating between children with asthma and those with airway obstruction due to other conditions.1

Normal spirometry in a child, especially when asymptomatic, does not exclude the diagnosis of asthma.1 FEV1 is often normal in children with persistent asthma.1

Reduced FEV1 alone does not indicate that a child has asthma, because it may be seen with other lung diseases (or be due to poor spirometric technique).

A significant increase in FEV1 (>12% from baseline) after administering a bronchodilator (e.g. 4 puffs of salbutamol 100 mcg/actuation) indicates that airflow limitation is reversible and supports the diagnosis of asthma. In children with asthma, it is also predictive of a good lung function response to inhaled corticosteroids.1 However, an absent response to bronchodilators does not exclude asthma.1

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Bronchial provocation (challenge) tests in children

Clinical assessment is more sensitive for confirming the diagnosis of asthma than tests for airway hyperresponsiveness.

The main roles of bronchial provocation (challenge) tests of airway hyperresponsiveness (airway hyperreactivity) are to confirm or exclude asthma as the cause of current symptoms, including exercise-associated respiratory symptoms such as dyspnoea or noisy breathing. 34

Challenge tests are performed in accredited lung function testing laboratories. These tests are usually difficult to perform in children under 8 years of age because they involve repeated spirometry tests.

If challenge testing is needed, consider referring to a paediatric respiratory physician for investigation, or discussing with a paediatric respiratory physician before selecting which test to order.

Do not test during a respiratory infection, or initiate inhaled corticosteroid treatment a few weeks before challenge testing, because these could invalidate the result.

Bronchial provocation tests of airway hyperresponsiveness include:

  • exercise challenge test5
  • mannitol challenge test67
  • methacholine challenge test.8, 9
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Roles of other lung function tests in diagnosing asthma in children

Peak expiratory flow meters in asthma diagnosis

Variability in lung function based on serial home measures of peak expiratory flow and FEV1 shows poor concordance with disease activity in children.1

Using a peak flow meter to measure peak expiratory flow in children does not reliably rule the diagnosis of asthma in or out.1

Newer tests under investigation

Impulse oscillometry, tests of specific airways resistance, and measurements of residual volume are being investigated for use in asthma diagnosis and management,10, 11 but their availability is mainly restricted to specialist and research centres.1

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References

  1. British Thoracic Society (BTS), Scottish Intercollegiate Guidelines Network (SIGN). British Guideline on the Management of Asthma. A national clinical guideline. BTS, SIGN, Edinburgh, 2012. Available from: https://www.brit-thoracic.org.uk/guidelines-and-quality-standards/asthma-guideline/
  2. Johns DP, Pierce R. Pocket guide to spirometry. 3rd edn. McGraw Hill, North Ryde, 2011.
  3. Anderson SD. Bronchial challenge tests: usefulness, availability and challenges. Breathe. 2011; 8: 53-60. Available from: http://www.ers-education.org
  4. Cockcroft DW. Direct challenge tests: airway hyperresponsiveness in asthma: its measurement and clinical significance. Chest. 2010; 138(2 Suppl): 18S-24S. Available from: http://journal.publications.chestnet.org/article.aspx?articleid=1086632
  5. Anderson SD, Pearlman DS, Rundell KW, et al. Reproducibility of the airway response to an exercise protocol standardized for intensity, duration, and inspired air conditions, in subjects with symptoms suggestive of asthma. Respir Res. 2010; Sept 1: 120. Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2939602/
  6. Barben J, Roberts M, Chew N, et al. Repeatability of bronchial responsiveness to mannitol dry powder in children with asthma. Pediatr Pulmonol. 2003; 36: 490-4. Available from: http://www.ncbi.nlm.nih.gov/pubmed/14618640
  7. Kersten ET, Driessen JM, van der Berg JD, Thio BJ. Mannitol and exercise challenge tests in asthmatic children. Pediatr Pulmonol. 2009; 44: 655-661. Available from: http://www.ncbi.nlm.nih.gov/pubmed/19499571
  8. Liem JJ, Kozyrskyj AL, Cockroft DW, Becker AB. Diagnosing asthma in children: what is the role for methacholine bronchoprovocation testing?. Pediatr Pulmonol. 2008; 43: 481-9. Available from: http://www.ncbi.nlm.nih.gov/pubmed/18383334
  9. Carlsten C, Dimich-Ward H, Ferguson A, et al. Airway hyperresponsiveness to methacholine in 7-year-old children: sensitivity and specificity for pediatric allergist-diagnosed asthma. Pediatr Pulmonol. 2011; 46: 175-178. Available from: http://www.ncbi.nlm.nih.gov/pubmed/20963839
  10. Child F. The measurement of airways resistance using the interrupter technique (Rint). Paediatr Respir Rev. 2005; 6: 273-7. Available from: http://www.ncbi.nlm.nih.gov/pubmed/16298310
  11. Oostveen E, MacLeod D, Lorino H, et al. The forced oscillation technique in clinical practice: methodology, recommendations and future developments. Eur Respir J Supplement. 2003; 22: 1026-41. Available from: http://erj.ersjournals.com/content/22/6/1026.long