Nội dung của trang này:
Nội dung của trang này:
Differential Diagnosis
When symptoms are not typical with asthma and lung function does not support asthma, consider other diagnoses. Failure to respond to asthma treatment should prompt the search for an alternative or additional diagnosis. Asthma symptoms are nonspecific and are shared with other diseases such as the following:
- Aspiration
- Bronchiectasis
- Cardiac disease
- Vocal cord dysfunction
- Hyperventilation syndrome and panic attacks
- Interstitial lung disease
- Tumor: Laryngeal, lung, tracheal
- Cystic fibrosis
- Chronic obstructive pulmonary disease
- Foreign body
- Pulmonary embolism
Difficult Diagnostic Groups
The following
are the difficult diagnostic groups that may require specialist referral.
In children ≤5 years
old, episodic wheezing and coughing are common in children, especially ages
<3 years. Diagnosis is based primarily on clinical judgment, evaluation of
symptoms, and physical findings. There are symptoms that are highly suggestive
of asthma such as recurrent wheezing, nocturnal cough not associated with a
viral infection, a wheeze that does not vary seasonally, and the presence of
symptoms after 3 years old. A trial of treatment with short-acting
bronchodilators and inhaled glucocorticosteroids may help confirm the diagnosis
in this age group.
*Please see Asthma disease management chart in the
latest edition of MIMS Pediatrics for further information.
The elderly population may present with wheezing,
breathlessness, and cough that are sometimes cardiac in etiology, hence, a thorough
history and physical exam, together with an electrocardiogram (ECG) and chest X-ray
may help distinguish a cardiac pathology.
Chronic obstructive pulmonary disease should be
differentiated from asthma by a trial of treatment with bronchodilators and/or
inhaled glucocorticosteroids wherein marked improvement after bronchodilator or
inhaled glucocorticoid suggests asthma.
Occupational asthma is acquired
in the workplace, usually caused by inhalant chemicals (eg isocyanates,
platinum salts, complex plant, and animal biological products). Diagnosis is
successfully confirmed with lung function measurement, particularly serial
measurement of peak expiratory flow at work and away from work, and specific
bronchial provocation testing. Seasonal asthma may occur intermittently with the
patient being entirely asymptomatic between seasons or may occur as a seasonal
worsening of symptoms in an asthmatic patient.
Cough variant asthma has the principal symptom of
chronic cough frequently during the night. Documentation of variability in lung
function or of airway hyperresponsiveness and the search for sputum
eosinophilia are important for possible diagnosis.
Patients
on Controller Treatment
For patients currently taking controller treatments
but have not been previously documented, confirming the diagnosis is based on the
presence of variable respiratory symptoms with variable airflow limitation.
For patients with variable respiratory symptoms
without variable airflow limitation, the bronchodilator reversibility test
should be repeated after withholding bronchodilator treatments. This may
indicate that controller treatment may need to be reassessed.
For patients with few respiratory symptoms, with no
variable airflow limitation, and normal lung function, withholding the bronchodilator
treatment before repeating the bronchodilator reversibility test should be
done. If the patient develops symptoms and the lung function worsens after the withdrawal
of treatments, the diagnosis is confirmed. If there is an absence of symptoms and
lung function remains the same after withdrawal of treatment, cessation of
controller treatments may be done.
The presence of dyspnea with fixed airflow
limitation may indicate the need to reassess the treatment regimen and further
management.