History
Guidelines from the National Asthma Education and Prevention Program, which were updated in 2007, highlight the importance of correctly diagnosing asthma. [2] To establish the diagnosis of asthma, the clinician must confirm the following:
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Episodic symptoms of airflow obstruction are present
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Airflow obstruction or symptoms are at least partially reversible
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Alternative diagnoses are excluded
Thus, obtaining a good patient history is crucial when diagnosing asthma and excluding other causes.
The clinician should establish whether the patient has any of the following symptoms:
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Wheezing
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Cough
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Cough at night
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Cough during or after exercise
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Shortness of breath
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Chest tightness
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Sputum production
The clinician should determine the pattern of symptoms, as follows:
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Perennial, seasonal, or both
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Continuous or intermittent
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Daytime or nighttime
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Onset and duration
The clinician should ask whether any of the following precipitate and/or aggravate symptoms:
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Viral infections
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Environmental allergens
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Irritants (eg, smoke exposure, chemicals, vapors, dust)
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Exercise
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Emotions
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Home environment (eg, carpets, pets, mold)
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Stress
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Drugs (eg, aspirin, beta blockers)
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Foods
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Changes in weather
The presence of other conditions that may affect asthma should be determined. Such conditions may include the following:
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Thyroid disease
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Pregnancy
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Menses
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Sinusitis
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Rhinitis
Questions about the development and treatment of the patient’s disease should touch on the following:
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Age at onset and diagnosis
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Progression of symptoms (better or worse)
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Improvement with bronchodilators
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Use of oral corticosteroids
The family history should include any history of asthma, allergy, sinusitis, rhinitis, eczema, or nasal polyps in close relatives, and the social history should cover factors that may contribute to nonadherence of asthma medications, as well as any illicit drug use.
The history of exacerbations should include the usual prodromal signs or symptoms, rapidity of onset, associated illnesses, number in the last year, and need for hospitalization. Symptoms of asthma may include wheezing, coughing, and chest tightness, among others. Patients with persistent asthmatic symptoms are more likely to experience severe asthma exacerbations. [42]
Wheezing
A musical, high-pitched, whistling sound produced by airflow turbulence is one of the most common symptoms. The wheezing usually occurs during exhalation.
In the mildest form, wheezing is only end expiratory. As severity increases, the wheeze lasts throughout expiration. In a more severe asthmatic episode, wheezing is also present during inspiration. During the most severe episodes, wheezing may be absent because of the severe limitation of airflow associated with airway narrowing and respiratory muscle fatigue.
Asthma can occur without wheezing when obstruction involves predominantly the small airways. Thus, wheezing is not necessary for the diagnosis of asthma. Furthermore, wheezing can be associated with other causes of airway obstruction, such as cystic fibrosis and heart failure.
Patients with vocal cord dysfunction have a predominantly inspiratory monophonic wheeze/sound (different from the polyphonic wheeze in asthma), which is heard best over the laryngeal area in the neck. Patients with bronchomalacia and tracheomalacia also have a monophonic wheeze.
In exercise-induced or nocturnal asthma, wheezing may be present after exercise or during the night, respectively.
Coughing and chest tightness
Cough may be the only symptom of asthma, especially in cases of exercise-induced or nocturnal asthma. Usually, the cough is nonproductive and nonparoxysmal. In addition, coughing may be present with wheezing. Children with nocturnal asthma tend to cough after midnight, during the early hours of morning. A history of tightness or pain in the chest may be present with or without other symptoms of asthma, especially in exercise-induced or nocturnal asthma.
Other nonspecific symptoms
Infants or young children may have a history of recurrent bronchitis, bronchiolitis, or pneumonia; a persistent cough with colds; and/or recurrent croup or chest rattling. Most children with chronic or recurrent bronchitis have asthma. Asthma is the most common underlying diagnosis in children with recurrent pneumonia. Older children may have a history of chest tightness and/or recurrent chest congestion.
In an acute episode, symptoms vary according to the severity of the episode. During a mild episode, patients may be breathless after physical activity such as walking. They can talk in sentences and lie down, and they may be agitated. During a moderate-to-severe episode, patients are breathless while talking. Infants have feeding difficulties and a softer, shorter cry.
During a severe episode, patients are breathless during rest, are not interested in feeding, sit upright, talk in words (not sentences), and are usually agitated. With imminent respiratory arrest (in addition to the aforementioned symptoms), the child is drowsy and confused. However, adolescents may not have these symptoms until they are in frank respiratory failure.
Physical Examination
The clinical picture of pediatric asthma varies. Symptoms may be associated with upper respiratory tract infections (URTIs), nocturnal or exercise-induced asthmatic symptoms, and status asthmaticus.
Status asthmaticus, or an acute severe asthmatic episode that is resistant to appropriate outpatient therapy, is a medical emergency that requires aggressive inpatient management. This may include admission to an ICU for the treatment of hypoxia, hypercarbia, and dehydration and possibly for assisted ventilation because of respiratory failure.
Physical findings vary with the absence or presence of an acute episode and its severity.
Findings in the absence of an acute episode
The physical findings between acute episodes vary with the severity of the asthma. During an outpatient visit, a patient with mild asthma may have normal findings on physical examination. Patients with more severe asthma are likely to have signs of chronic respiratory distress and chronic hyperinflation.
Signs of atopy or allergic rhinitis, such as conjunctival congestion and inflammation, ocular shiners, a transverse crease on the nose due to constant rubbing associated with allergic rhinitis, and pale violaceous nasal mucosa due to allergic rhinitis, may be present.
The anteroposterior diameter of the chest may be increased because of hyperinflation. Hyperinflation may also cause an abdominal breathing pattern.
Lung examination may reveal prolongation of the expiratory phase, expiratory wheezing, coarse crackles, or unequal breath sounds. In a child who is not sick, forced exhalation may reveal expiratory wheeze. Forced exhalation can be obtained by asking the child to blow hard (like blowing imaginary birthday candles) or, in the case of toddlers or infants, pushing on the abdomen may be used to cause forced exhalation. Clubbing of the fingers is not a feature of straightforward asthma and indicates a need for more extensive evaluation and work-up to exclude other conditions, such as cystic fibrosis.
Findings during an acute episode
Physical examination during an acute episode may reveal different findings in mild, moderately severe, and severe episodes and in status asthmaticus with often imminent respiratory arrest.
Findings during a mild episode include the following:
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Increased respiratory rate
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Accessory muscles of respiration are not used
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The heart rate is less than 100 beats per minute
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Pulsus paradoxus is not present
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Auscultation of chest reveals moderate wheezing, which is often end expiratory
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Oxyhemoglobin saturation with room air is greater than 95%
Findings during a moderately severe episode include the following:
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Increased respiratory rate
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Accessory muscles of respiration typically are used
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Suprasternal retractions are present
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The heart rate is 100-120 beats per minute
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Loud expiratory wheezing can be heard
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Pulsus paradoxus may be present (10-20 mm Hg)
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Oxyhemoglobin saturation with room air is 91-95%
Findings during a severe episode include the following:
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The respiratory rate is often greater than 30 breaths per minute
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Accessory muscles of respiration are usually used
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Suprasternal retractions are commonly present
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The heart rate is greater than 120 beats per minute
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Loud biphasic (expiratory and inspiratory) wheezing can be heard
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Pulsus paradoxus is often present (20-40 mm Hg)
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Oxyhemoglobin saturation with room air is less than 91%.
Findings in status asthmaticus with often imminent respiratory arrest include the following:
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Paradoxical thoracoabdominal movement
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Wheezing may be absent (in patients with the most severe airway obstruction)
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Severe hypoxemia may manifest as bradycardia
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Pulsus paradoxus may disappear; this finding suggests respiratory muscle fatigue
Staging
Asthma severity is defined as "the intensity of the disease process" prior to the initiation of therapy. Defining asthma severity helps in determining the initiation of therapy in a patient who is not on any controller medications. [2]
The severity of asthma is classified as intermittent, mild persistent, moderate persistent, or severe persistent. This classification is based on the impairment and risk related to disease, which is measured by the following:
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Frequency and severity of symptoms, including nocturnal symptoms
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Characteristics of acute episodes
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Pulmonary function
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Exacerbations
Features of these categories have been divided into 3 charts to reflect classification in different age groups (0-4 y, 5-11 y, and 12 y and older), according to the 2007 National Asthma Education and Prevention Program guidelines. [2]
An important point to remember is that the presence of one severe feature is sufficient to diagnose severe persistent asthma. In addition, the characteristics in this classification system are general and may overlap because asthma severity varies widely. In addition, a patient’s classification may change over time .
Patients with asthma of any level of severity may have mild, moderate, or severe exacerbations.
Some patients with intermittent asthma have severe and life-threatening exacerbations separated by episodes with almost normal lung function and minimal symptoms; however, they are likely to have other evidence of increased BHR (eg, on exercise or challenge testing) due to ongoing inflammation.
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- Overview
- Presentation
- DDx
- Workup
- Treatment
- Guidelines
- Medication
- Medication Summary
- Bronchodilators, Beta2-Agonists
- Nonracemic Form of the Beta2-Agonist Albuterol
- Long-Acting Beta2-Agonists
- Inhaled Corticosteroids
- Systemic Corticosteroids
- Leukotriene Modifiers
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