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Asthma - Diagnosis
Diagnosis of Asthma in Adults
and Children Over 5 Years of Age
Recurrent episodes of coughing or wheezing are
almost always due to asthma in both children
and adults. Cough can be the sole symptom.
Findings that increase the probability of asthma
include:
Medical history:
- Episodic wheeze, chest tightness, shortness of
breath, or cough.
- Symptoms worsen in presence of aeroallergens,
irritants, or exercise.
- Symptoms occur or worsen at night, awakening
the patient.
- Patient has allergic rhinitis or atopic dermatitis.
- Close relatives have asthma, allergy, sinusitis, or
rhinitis.
Physical examination of the upper
respiratory tract, chest, and skin:
- Hyperexpansion of the thorax
- Sounds of wheezing during normal breathing or
a prolonged phase of forced exhalation
- Increased nasal secretions, mucosal swelling,
sinusitis, rhinitis, or nasal polyps
- Atopic dermatitis/eczema or other signs of allergic
skin problems
To establish an asthma diagnosis, determine
the following:
- History or presence of episodic symptoms of
airflow obstruction (i.e., wheeze, shortness of
breath, tightness in the chest, or cough). Asthma
symptoms vary throughout the day; absence of
symptoms at the time of the examination does not
exclude the diagnosis of asthma.
- Airflow obstruction is at least partially
reversible. Use spirometry to:
Establish airflow obstruction: FEV 1 <80
percent predicted; FEV 1 /FVC* <65 percent or
below the lower limit of normal. (If obstruction is
absent, see Additional Tests, page 5.)
Establish reversibility: FEV 1 increases > _12 percent
and at least 200 mL after using a short-acting
inhaled beta 2 -agonist (e.g., albuterol, terbutaline).
NOTE: Older adults may need to take oral steroids for 2 to 3
weeks and then take the spirometry test to measure the degree of
reversibility achieved. Chronic bronchitis and emphysema may
coexist with asthma in adults. The degree of reversibility indicates
the degree to which asthma therapy may be beneficial.
- Alternative diagnoses are excluded (e.g., vocal
cord dysfunction, vascular rings, foreign bodies,
or other pulmonary diseases). See page 5 for
additional tests that may be needed.
In general, FEV 1 predicted norms or reference values
used for children should also be used for adolescents.
Diagnosis of Asthma in Adults
and Children Over 5 Years of Age
Recurrent episodes of coughing or wheezing are
almost always due to asthma in both children
and adults.
Cough can be the sole symptom.
Findings that increase the probability of asthma
include:
Medical history:
- Episodic wheeze, chest tightness, shortness of
breath, or cough.
- Symptoms worsen in presence of aeroallergens,
irritants, or exercise.
- Symptoms occur or worsen at night, awakening
the patient.
- Patient has allergic rhinitis or atopic dermatitis.
- Close relatives have asthma, allergy, sinusitis, or
rhinitis.
Physical examination of the upper
respiratory tract, chest, and skin:
- Hyperexpansion of the thorax
- Sounds of wheezing during normal breathing or
a prolonged phase of forced exhalation
- Increased nasal secretions, mucosal swelling,
sinusitis, rhinitis, or nasal polyps
- Atopic dermatitis/eczema or other signs of allergic
skin problems
To establish an asthma diagnosis, determine
the following:
- History or presence of episodic symptoms of
airflow obstruction (i.e., wheeze, shortness of
breath, tightness in the chest, or cough). Asthma
symptoms vary throughout the day; absence of
symptoms at the time of the examination does not
exclude the diagnosis of asthma.
- Airflow obstruction is at least partially
reversible. Use spirometry to:
Establish airflow obstruction: FEV 1 <80
percent predicted; FEV 1 /FVC* <65 percent or
below the lower limit of normal. (If obstruction is
absent, see Additional Tests, page 5.)
Establish reversibility: FEV 1 increases > _12 percent
and at least 200 mL after using a short-acting
inhaled beta 2 agonist (e.g., albuterol, terbutaline).
NOTE: Older adults may need to take oral steroids for 2 to 3
weeks and then take the spirometry test to measure the degree of
reversibility achieved. Chronic bronchitis and emphysema may
coexist with asthma in adults. The degree of reversibility indicates
the degree to which asthma therapy may be beneficial.
- Alternative diagnoses are excluded (e.g., vocal
cord dysfunction, vascular rings, foreign bodies,
or other pulmonary diseases). See page 5 for
additional tests that may be needed.
In general, FEV 1 predicted norms or reference values
used for children should also be used for adolescents.
Diagnosis in Infants and Children
Younger Than 5 Years of Age
Because children with asthma are often
mislabeled as having bronchiolitis, bronchitis,
or pneumonia, many do not receive adequate
therapy.
- The diagnostic steps listed previously are the same for
this age group except that spirometry is not possible.
A trial of asthma medications may aid in the eventual
diagnosis.
- Diagnosis is not needed to begin to treat wheezing
associated with an upper respiratory viral infection,
which is the most common precipitant of wheezing
in this age group. Patients should be monitored
carefully.
- There are two general patterns of illness in infants and
children who have wheezing with acute viral upper respiratory
infections: a remission of symptoms in the
preschool years and persistence of asthma throughout
childhood. The factors associated with continuing
asthma are allergies, a family history of asthma, and
perinatal exposure to aeroallergens and passive smoke.
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