British guideline
on the management of asthma in adults
The British Thoracic Society & Scottish Intercollegiate Guidelines Network
SIGN: Edinburgh, 2008 (revised 2009)
Diagnosis
- The diagnosis of asthma is based on the recognition of a characteristic
pattern of symptoms and signs and the absence of an alternative explanation
for them. The key is to take a careful clinical history
- Base initial diagnosis on a careful assessment of symptoms and
a measure of airflow obstruction:
- in patients with a high probability of asthma move
straight to a trial of treatment. Reserve further testing for
those whose treatment is poor
- in patients with a low probability of asthma, whose
symptoms are thought to be due to an alternative diagnosis, investigate
and manage accordingly. Reconsider the diagnosis in those who
do not respond
- the preferred approach in patients with an intermediate
probability of having asthma is to carry out further investigations,
including an explicit trial of treatments for a specified period,
before confirming a diagnosis and establishing maintenance
treatment
- Spirometry is the preferred initial test to assess the presence
and severity of airflow obstruction
- Clinical features that increase the probability of asthma:
- more than one of the following symptoms: wheeze, breathlessness,
chest tightness, and cough, particularly if symptoms are:
- worse at night and in the early morning
- in response to exercise, allergen exposure, and cold air
- after taking aspirin or beta blockers
- history of atopic disorder
- family history of asthma and/or atopic disorder
- widespread wheeze heard on auscultation of the chest
- otherwise unexplained low FEV1 or
PEF (historical or serial readings)
- otherwise unexplained peripheral blood eosinophilia
- Clinical features that lower the probability of asthma
- prominent dizziness, light-headedness, peripheral tingling
- chronic productive cough in the absence of wheeze or breathlessness
- repeatedly normal physical examination of chest when symptomatic
- voice disturbance
- symptoms with colds only
- significant smoking history (i.e.>20 pack years)
- cardiac disease
- normal PEF or spirometry when symptomatic
- A normal spirogram/spirometry when not symptomatic does not exclude
the diagnosis of asthma. Repeated measurements of lung function are
often more informative than a single assessment
