Asthma Management Handbook

Checking whether the symptoms are due to asthma

Recommendations

Take a thorough history of respiratory symptoms, beginning from before the diagnosis of asthma was made. (If the patient is a child, start from birth.) Ask about:

  • symptoms
  • factors that seem to worsen or improve asthma
  • medical history
  • medicines, including over-the-counter and complementary medicines.
How this recommendation was developed

Consensus

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

For patients who report the diagnosis of asthma made in the past or elsewhere, confirm the diagnosis if possible.

Table. Confirming the diagnosis of asthma in a person using preventer treatment Opens in a new window Please view and print this figure separately: http://www.asthmahandbook.org.au/table/show/9

How this recommendation was developed

Consensus

Based on clinical experience and expert opinion (informed by evidence, where available), with particular reference to the following source(s):

  • Aaron et al. 20081
  • Lucas et al. 20082
  • Luks et al. 20103
  • Marklund et al. 19994

Consider the possibility of alternative and concurrent diagnoses.

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

Asthma is more likely to explain the symptoms if any of these apply

Asthma is less likely to explain the symptoms if any of these apply

More than one of these symptoms:

  • wheeze
  • breathlessness
  • chest tightness
  • cough

Symptoms recurrent or seasonal

Symptoms worse at night or in the early morning

History of allergies (e.g. allergic rhinitis, atopic dermatitis)

Symptoms obviously triggered by exercise, cold air, irritants, medicines (e.g. aspirin or beta blockers), allergies, viral infections, laughter

Family history of asthma or allergies

Symptoms began in childhood

Widespread wheeze audible on chest auscultation

FEV1 or PEF lower than predicted, without other explanation

Eosinophilia or raised blood IgE level, without other explanation

Symptoms rapidly relieved by a SABA bronchodilator

Dizziness, light-headedness, peripheral tingling

Isolated cough with no other respiratory symptoms

Chronic sputum production

No abnormalities on physical examination of chest when symptomatic (over several visits)

Change in voice

Symptoms only present during upper respiratory tract infections

Heavy smoker (now or in past)

Cardiovascular disease

Normal spirometry or PEF when symptomatic (despite repeated tests)

Adapted from:

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

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/.

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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 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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How this recommendation was developed

Consensus

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

More information

Confirming the diagnosis of asthma in adults and adolescents

A prior diagnosis of asthma reported by a patient should be corroborated by documentation of how the diagnosis was confirmed at the time, or by current evidence.

Reports from around the world show that 25–35% of people with a diagnosis of asthma in primary care may not actually have asthma.2345 Wheezing and other respiratory symptoms do not always mean a person has asthma. Airflow limitation demonstrated on spirometry can be transient and does not necessarily mean that the person has asthma (e.g. when recorded during a severe acute viral infection of the respiratory tract). Ideally, airflow limitation should be confirmed when the patient does not have a respiratory tract infection.

Once a person is already taking regular treatment with a preventer, it may be more difficult to confirm the diagnosis because variability in lung function often decreases with treatment.

Table. Confirming the diagnosis of asthma in a person using preventer treatment Opens in a new window Please view and print this figure separately: http://www.asthmahandbook.org.au/table/show/9

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Upper airway dysfunction

Upper airway dysfunction is intermittent, abnormal adduction of the vocal cords during respiration, resulting in variable upper airway obstruction. It often mimics asthma67 and is commonly misdiagnosed as asthma.89 It can cause severe acute episodes of dyspnoea that occur either unpredictably or due to exercise.8 Inspiratory stridor associated with vocal cord dysfunction is often described as ‘wheezing’,8 but symptoms do not respond to asthma treatment.710

Upper airway dysfunction can coexist with asthma.6 People with asthma who also have upper airway dysfunction experience more symptoms than those with asthma alone and this can result in over-treatment if vocal cord dysfunction is not identified and managed appropriately.6

Upper airway dysfunction probably has multiple causes.6 In some people it is probably due to hyperresponsiveness of the larynx in response to intrinsic and extrinsic triggers.611 Triggers can include exercise, psychological conditions, airborne irritants, rhinosinusitis, gastro-esophageal reflux disease, and medicines.79

Upper airway dysfunction should be considered when spirometry shows normal FEV1/FVC ratio in a patient with suspected asthma9 or symptoms do not respond to short-acting beta2 agonist reliever. The shape of the maximal respiratory flow loop obtained by spirometry may suggest the diagnosis.8 Direct observation of the vocal cords is the best method to confirm the diagnosis of upper airway dysfunction.6

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Cough and asthma in adults

When no other asthma symptoms are present, chronic cough (present for more than 8 weeks) is unlikely to indicate asthma.

Chronic cough may be due to asthma if:12

  • cough is episodic
  • cough with exercise is associated with other symptoms that suggest airflow limitation (expiratory wheeze or breathlessness)
  • spirometry confirms reversible airflow limitation.

If cough is due to asthma, it should respond to treatment with an inhaled corticosteroid preventer taken regularly and reliever as needed).12

Findings that suggest a serious alternative or comorbid diagnosis that requires further investigation include:12

  • haemoptysis
  • smoker with > 20 pack–year smoking history
  • smoker aged over 45 years with a new cough, altered cough, or cough with voice disturbance
  • prominent dyspnoea, especially at rest or at night
  • substantial sputum production
  • hoarseness
  • fever
  • weight loss
  • complicated gastro-oesophageal reflux disease
  • swallowing disorders with choking or vomiting
  • recurrent pneumonia
  • abnormal clinical respiratory examination.
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Cough and asthma in children

Relationship of cough to asthma in children

  • Misdiagnosis of nonspecific cough as asthma can result in overtreatment in children.
  • Cough can indicate the possibility of a serious underlying illness and warrant further assessment and investigations.12

Table. Red flags for cough in children

Wet or productive cough lasting more than 4 weeks

Obvious difficulty breathing, especially at rest or at night

Systemic symptoms: fever, failure to thrive or poor growth velocity

Feeding difficulties (including choking or vomiting)

Recurrent pneumonia

Inspiratory stridor (other than during acute tracheobronchitis)

Abnormalities on respiratory examination

Abnormal findings on chest X-ray

‘Clubbing’ of fingers

Source

Gibson PG, Chang AB, Glasgow NJ et al., CICADA: Cough in Children and Adults: Diagnosis and Assessment. Australian cough guidelines summary statement. Med J Aust, 2010; 192: 265-71. Available from: http://www.ncbi.nlm.nih.gov/pubmed/20201760

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Chronic cough (cough lasting more than 4 weeks) without other features of asthma is unlikely to be due to asthma.12

Cough is a frequent symptom in children with asthma, but may have a different mechanism from other symptoms of asthma (e.g. wheeze, chest tightness or breathlessness). Children who have recurrent cough, but do not wheeze, are unlikely to have asthma.13 A very small minority of children with recurrent nocturnal cough, but no other asthma symptoms, may be considered to have a diagnosis of atypical asthma.13  This diagnosis should be only made in consultation  with a paediatric respiratory physician.

In children with no abnormalities detected on physical examination, chest X-ray or spirometry, and no wheezing or breathlessness, chronic cough is most likely:12

  • due to protracted bacterial bronchitis (resolves with 2–6 weeks’ treatment with antibiotics)12
  • post-viral (resolves with time)
  • due to exposure to tobacco smoke and other pollutants.12

Frequency of cough reported by parents correlates poorly with frequency measured using diary cards or by audio recording monitors.14

0-5 years

Most cases of coughing in preschool children are not due to asthma:

  • Recurrent cough in preschool children, in the absence of other signs, is most likely due to recurrent viral bronchitis. Cough due to viral infection is unresponsive to bronchodilators and preventers such as montelukast, cromones or inhaled corticosteroids.
  • Children attending day care or preschool can have a succession of viral infections that merge into each other,14 giving the false appearance of chronic cough (cough lasting more than 4 weeks).

In preschool-aged children, cough may be due to asthma when it occurs during episodes of wheezing and breathlessness or when the child does not have a cold.

6 years and over

Chronic cough may be due to asthma if the cough is episodic and associated with other features of asthma such as expiratory wheeze, exercise-related breathlessness, or airflow limitation objectively demonstrated by spirometry (particularly if responsive to a bronchodilator).12

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Alternative diagnoses in children

Other conditions characterised by wheezing, breathlessness or cough can be confused with asthma. These include:

  • protracted bacterial bronchitis1215
  • habit-cough syndrome12
  • upper airway dysfunction.8

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 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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Definition of variable expiratory airflow limitation

Most of the tests for variable expiratory airflow limitation are based on showing variability in FEV1. While reduced FEV1 may be seen with many other lung diseases (or due to poor spirometric technique), a reduced ratio of FEV1 to FVC indicates airflow limitation.16 Normal FEV1/FVC values derived from population studies vary,1718 but are usually greater than:17

  • 0.85 in people aged up to 19 years
  • 0.80 in people aged 20–39 years
  • 0.75 in people aged 40–59 years
  • 0.70 in people aged 60–80 years.

In children, it is less useful to define expiratory airflow limitation according to a specific cut-off for FEV1/FVC ratio, because normal values in children change considerably with age.18

Some spirometers provide predicted normal values specific to age group. If these are available, a FEV1/FVC ratio less than the lower limit of normal (i.e. less than the 5th percentile of normal population) indicates airflow limitation.

Variable expiratory airflow limitation (beyond the range seen in healthy populations) can be documented if any of the following are recorded:

  • a clinically important increase in FEV1 (change in FEV1 of at least 200 mL and 12% from baseline for adults, or at least 12% from baseline for children) 10–15 minutes after administration of bronchodilator
  • clinically important variation in lung function (at least 20% change in FEV1) when measured repeatedly over time (e.g. spirometry on separate visits)
  • a clinically important reduction in lung function (decrease in FEV1 of at least 200 mL and 12% from baseline on spirometry, or decrease in peak expiratory flow rate by at least 20%) after exercise (formal laboratory-based exercise challenge testing uses different criteria for exercise-induced bronchoconstriction)
  • a clinically important increase in lung function (at least 200 mL and 12% from baseline) after a trial of 4 or more weeks of treatment with an inhaled corticosteroid
  • clinically important variation in peak expiratory flow (diurnal variability of more than 10%)
  • a clinically important reduction in lung function (15–20%, depending on the test) during a test for airway hyperresponsiveness (exercise challenge test or bronchial provocation test) measured by a respiratory function laboratory.

Notes

Patients referred to a respiratory function laboratory may be asked not to take certain medicines within a few hours to days before a spirometry visit.

A clinically important increase or decrease in lung function is defined as a change in FEV1 of at least 200 mL and 12% from baseline for adults, or at least 12% from baseline for children, or a change in peak expiratory flow rate of at least 20% on the same meter.1916 A clinically important increase in FVC after administering bronchodilator may also indicate reversible airflow limitation, but FVC is a less reliable measure in primary care because FVC may vary due to factors such as variation in inspiratory volume or expiratory time.

The finding of ‘normal’ lung function during symptoms reduces the probability that a patient has asthma, but a clinically important improvement in response to bronchodilator or inhaled corticosteroid can occur in patients whose baseline value is within the predicted normal range.

The greater the variation in lung function, the more certain is the diagnosis of asthma. However, people with longstanding asthma may develop fixed airflow limitation.

Reversibility in airflow limitation may not be detected if the person is already taking a long-acting beta2 agonist or inhaled corticosteroid.

Airflow limitation can be transient and does not necessarily mean that the person has asthma (e.g. when recorded during a severe acute infection of the respiratory tract). Ideally, airflow limitation should be confirmed when the patient does not have a respiratory tract infection. Reduction in lung function during a respiratory tract infection with improvement in lung function after its resolution, commonly occurs in people with asthma, but can also be seen in patients with COPD or in healthy people without either asthma or COPD.20,21

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References

  1. Aaron SD, Vandemheen KL, Boulet LP, et al. Overdiagnosis of asthma in obese and nonobese adults. CMAJ. 2008; 179: 1121-1131. Available from: http://www.cmaj.ca/content/179/11/1121.full
  2. Lucas AE, Smeenk FW, Smeele IJ, van Schayck CP. Overtreatment with inhaled corticosteroids and diagnostic problems in primary care patients, an exploratory study. Fam Pract. 2008; 25: 86-91. Available from: http://fampra.oxfordjournals.org/content/25/2/86.full
  3. Luks VP, Vandemheen KL, Aaron SD. Confirmation of asthma in an era of overdiagnosis. Eur Respir J. 2010; 36: 255-260. Available from: http://erj.ersjournals.com/content/36/2/255.full
  4. Marklund B, Tunsäter A, Bengtsson C. How often is the diagnosis bronchial asthma correct?. Fam Pract. 1999; 16: 112-116. Available from: http://fampra.oxfordjournals.org/content/16/2/112.full
  5. Aaron SD, Fergusson D, Dent R, et al. Effect of weight reduction on respiratory function and airway reactivity in obese women. Chest. 2004; 125: 2046-52. Available from: http://www.ncbi.nlm.nih.gov/pubmed/15189920
  6. Benninger C, Parsons JP, Mastronarde JG. Vocal cord dysfunction and asthma. Curr Opin Pulm Med. 2011; 17: 45-49. Available from: http://www.ncbi.nlm.nih.gov/pubmed/21330824
  7. Deckert J, Deckert L. Vocal cord dysfunction. Am Fam Physician. 2010; 81: 156-159. Available from: http://www.aafp.org/afp/2010/0115/p156.html
  8. Weinberger M, Abu-Hasan M. Pseudo-asthma: when cough, wheezing, and dyspnea are not asthma. Pediatrics. 2007; 120: 855-864. Available from: http://pediatrics.aappublications.org/content/120/4/855.full
  9. Morris MJ, Christopher KL. Diagnostic criteria for the classification of vocal cord dysfunction. Chest. 2010; 138: 1213-23. Available from: http://journal.publications.chestnet.org/article.aspx?articleid=1045155
  10. Kenn K, Balkissoon R. Vocal cord dysfunction: what do we know?. Eur Respir J. 2011; 37: 194-200. Available from: http://erj.ersjournals.com/content/37/1/194.long
  11. Gimenez LM, Zafra H. Vocal cord dysfunction: an update. Ann Allergy Asthma Immunol. 2011; 106: 267-274. Available from: http://www.ncbi.nlm.nih.gov/pubmed/21457874
  12. Gibson PG, Chang AB, Glasgow NJ, et al. CICADA: cough in children and adults: diagnosis and assessment. Australian cough guidelines summary statement. Med J Aust. 2010; 192: 265-271. Available from: http://www.lungfoundation.com.au/professional-resources/guidelines/cough-guidelines
  13. van Asperen PP. Cough and asthma. Paediatr Resp Rev. 2006; 7: 26-30. Available from: http://www.ncbi.nlm.nih.gov/pubmed/16473813
  14. Bush A. Diagnosis of asthma in children under five. Prim Care Respir J. 2007; 16: 7-15. Available from: http://www.ncbi.nlm.nih.gov/pubmed/17297521
  15. Craven V, Everard ML. Protracted bacterial bronchitis: reinventing an old disease. Arch Dis Child. 2013; 98: 72-76. Available from: http://www.ncbi.nlm.nih.gov/pubmed/23175647
  16. Pellegrino R, Viegi G, Brusasco V, et al. Interpretative strategies for lung function tests. Eur Respir J. 2005; 26: 948-968. Available from: http://erj.ersjournals.com/content/26/5/948
  17. National Heart Lung and Blood Institute (NHLBI) National Asthma Education and Prevention Program. Expert Panel Report 3: guidelines for the diagnosis and management of asthma. Full report 2007. US Department of Health and Human Services National Institutes of Health, Bethesda, 2007. Available from: http://www.nhlbi.nih.gov/health-pro/guidelines/current/asthma-guidelines/full-report
  18. Quanjer PH, Stanojevic S, Cole TJ, et al. Multi-ethnic reference values for spirometry for the 3-95-yr age range: the global lung function 2012 equations. Eur Respir J. 2012; 40: 1324-43. Available from: http://www.ncbi.nlm.nih.gov/pubmed/22743675
  19. Levy ML, Quanjer PH, Booker R, et al. Diagnostic Spirometry in Primary Care: Proposed standards for general practice compliant with American Thoracic Society and European Respiratory Society recommendations. Prim Care Respir J. 2009; 18: 130-147. Available from: http://www.ncbi.nlm.nih.gov/pubmed/19684995
  20. Collier AM, Pimmel RL, Hasselblad V, et al. Spirometric changes in normal children with upper respiratory infections. Am Rev Respir Dis. 1978; 117: 47-53. Available from: http://www.ncbi.nlm.nih.gov/pubmed/619724
  21. Melbye H, Kongerud J, Vorland L. Reversible airflow limitation in adults with respiratory infection. Eur Respir J. 1994; 7: 1239-1245. Available from: http://www.ncbi.nlm.nih.gov/pubmed/7925901