Making a correct diagnosis is tremendously important because if asthma is correctly diagnosed it can be treated
- A diagnosis of asthma involves all of the following:
- A detailed history which would include:
- A family history of asthma, allergies, hay fever and eczema; children will have a greater chance of
developing the above if there is a family history of allergies and asthma
- A child's medical history including:
- When parents first noticed the child developed breathing problems; history of nasal stuffiness (rhinitis),
itchy eyes (allergic conjunctivitis) and eczema, which are common accompaniments to asthma, and hives
- A history of recurrent and persistent cough following a cold, frequent colds, croup, seasonal changes (i.e.
worse in the spring and autumn), exercise limited by breathing problems, waking at night with symptoms.
- school absences, emergency room visits (hospitalizations)
- environmental history
- Physical examination: i.e. listening to the lungs with a stethoscope; examination of nasal passages
- Chest x-ray to exclude the likelihood of breathing problems being caused by something other than
- Blood tests and sputum studies.
- Allergy prick skin testing: Skin tests can confirm a presence or absence of allergies; but they must, be
correlated to the history of symptoms shown.
- Spirometry If testing children who are less than five years old, this test is not commonly indicated
because a certain amount of effort and cooperation is required. However, it's a very good trustworthy method of
making an asthma diagnosis. Any difficult or troublesome asthma should be confirmed objectively by performing a
- Challenge tests: Exercise challenge tests and methacholine inhalation tests are procedures which are used
most frequently in clinical laboratories to assess airway responsiveness.
- Differential diagnosis: Other possible causes of shortness of breath, wheeze, and cough plus chest
tightness need to be investigated in order to rule them out. These can include such illnesses as heart disease,
other lung conditions and gastro-oesophageal reflux.
- A trial use of asthma medications: If asthma medications are taken and an improvement in symptoms is seen
this further supports a diagnosis of asthma.
Tests may include:
- Peak expiratory flow charts
- Exercise tests
- Histamine or methacholine bronchial provocation test
- A trial of corticosteroids
- Blood and sputum tests
- Chest X-ray
- Skin tests
- Allergen provocation tests
Peak expiratory flow charts
Measurements of PEFR on waking, prior to taking a bronchodilator
medication and before bed after a bronchodilator, are very useful in demonstrating the variable airflow limitations
characterizing asthma. It's also useful in the longer-term evaluation of the sufferer's disease and its
response to proffered treatment. Peak flows should always be measured over several days and preferably over a
weekend or short holiday if the effect of the asthma sufferer's work exposure is also being studied.
These are widely used in the diagnosis of asthma in children. Ideally, the child should run for 6 minutes on a
treadmill at a workload which is sufficient to increase their heart rate above 160 beats per minute. Alternative
methods use cold air challenge.
This test indicates the presence of airway hyper responsiveness, which is a
feature found in most asthmatics. It can be predominantly useful in investigating those people whose main symptom
is a cough.