History
A detailed assessment of the medical history should address the following:
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Whether symptoms are attributable to asthma
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Whether findings support the likelihood of asthma (eg, family history)
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Asthma severity
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Identification of possible precipitating factors
Family history may be pertinent for asthma, allergy, sinusitis, rhinitis, eczema, and nasal polyps. The social history may include home characteristics, smoking, workplace or school characteristics, educational level, employment, social support, factors that may contribute to nonadherence of asthma medications, and illicit drug use.
The patient’s exacerbation history is important with respect to the following:
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Usual prodromal signs or symptoms
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Rapidity of onset
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Associated illnesses
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Number in the last year
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Need for emergency department visits, hospitalizations, ICU admissions, intubations
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Missed days from work or school or activity limitation
The patient’s perception of his or her asthma is important regarding knowledge of asthma and treatment, use of medications, coping mechanisms, family support, and economic resources.
General manifestations of asthma
Wheezing, a musical, high-pitched, whistling sound produced by airflow turbulence, is one of the most common symptoms. 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 a most severe episode, 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, now referred to as inducible laryngeal obstruction (ILO), have a predominantly inspiratory monophonic wheeze (different from the polyphonic wheeze in asthma), which is heard best over the laryngeal area in the neck. Patients with excessive dynamic airway collapse (EDAC), bronchomalacia, or tracheomalacia also have an expiratory monophonic wheeze heard over the large airways. In exercise-induced bronchoconstriction, wheezing may be present after exercise, and in nocturnal asthma, wheezing is present during the night.
Cough may be the only symptom of asthma, especially in cases of exercise-induced or nocturnal asthma. Usually, the cough is nonproductive and nonparoxysmal. Children with nocturnal asthma tend to cough after midnight and during the early hours of morning. Chest tightness or 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 in infants or young children may be 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 also the most common underlying diagnosis in children with recurrent pneumonia; older children may have a history of chest tightness and/or recurrent chest congestion.
Exercise-induced bronchoconstriction
In patients with exercise-induced bronchoconstriction, the clinical history findings are typical of asthma but are associated only with exercise. Typical symptoms include cough, wheezing, shortness of breath, and chest pain or tightness. Some individuals also may report sore throat or GI upset. Initially, airway dilation is noted during exercise. If exercise continues beyond approximately 10 minutes, bronchoconstriction supervenes, resulting in asthma symptoms. If the exercise period is shorter, symptoms may develop up to 5-10 minutes after completion of exercise. Higher intensity levels of exercise result in a more intense attack, with running producing more symptoms than walking.
Patients may note asthma symptoms are related to seasonal changes or the ambient temperature and humidity in the environment in which a patient exercises. Other triggers may be pollutants (eg, sulfur, nitrous oxide, ozone) or upper respiratory tract infections. Cold, dry air generally provokes more obstruction than warm, humid air. Consequently, many athletes have good exercise tolerance in sports such as swimming. A prospective longitudinal study in Britain found that swimming was associated with increased lung function and lower risk of asthma-related symptoms, especially among children with respiratory conditions. [44]
Athletes who are more physically fit may not notice the typical asthma symptoms and may report only a reduced or more limited level of endurance. Several modifiers in the history should prompt an evaluation for causes other than exercise-induced bronchoconstriction. While patients may report typical obstructive symptoms, a history of a choking sensation with exercise, inspiratory wheezing, or stridor should prompt an evaluation for evidence of vocal cord dysfunction.
Physical Examination
The guidelines from the National Asthma Education and Prevention Program highlight the importance of correctly diagnosing asthma, by establishing the following [1] :
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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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Exclusion of alternative diagnoses.
Manifestations of an acute episode
Acute episodes can be mild, moderately severe, severe, or characterized by imminent respiratory arrest.
Mild episodes
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. Patients with mild acute asthma are able to lie flat. In a mild episode, the respiratory rate is increased, and accessory muscles of respiration are not used. The heart rate is less than 100 bpm, and pulsus paradoxus (an exaggerated fall in systolic blood pressure during inspiration) is not present. Auscultation of the chest reveals moderate wheezing, which is often end expiratory. Rapid forced expiration may elicit wheezing that is otherwise inaudible, and oxyhemoglobin saturation with room air is greater than 95%.
Moderately severe episodes
In a moderately severe episode, the respiratory rate also is increased. Typically, accessory muscles of respiration are used. In children, also look for supraclavicular and intercostal retractions and nasal flaring, as well as abdominal breathing. The heart rate is 100-120 bpm. Loud expiratory wheezing can be heard, and pulsus paradoxus may be present (10-20 mm Hg). Oxyhemoglobin saturation with room air is 91-95%. Patients experiencing a moderately severe episode are breathless while talking, and infants have feeding difficulties and a softer, shorter cry. In more severe cases, the patient assumes a sitting position.
Severe episodes
In a severe episode, patients are breathless during rest, are not interested in eating, sit upright, talk in words rather than sentences, and are usually agitated. In a severe episode, the respiratory rate is often greater than 30 per minute. Accessory muscles of respiration are usually used, and suprasternal retractions are commonly present. The heart rate is more than 120 bpm. Loud biphasic (expiratory and inspiratory) wheezing can be heard, and pulsus paradoxus is often present (20-40 mm Hg). Oxyhemoglobin saturation with room air is less than 91%. As the severity increases, the patient increasingly assumes a hunched-over sitting position with the hands supporting the torso, termed the tripod position.
Imminent respiratory arrest
When children are in imminent respiratory arrest, in addition to the aforementioned symptoms, they are drowsy and confused, but adolescents may not have these symptoms until they are in frank respiratory failure. In status asthmaticus with imminent respiratory arrest, paradoxical thoracoabdominal movement occurs. Wheezing may be absent (associated with most severe airway obstruction), and severe hypoxemia may manifest as bradycardia. Pulsus paradoxus noted earlier may be absent; this finding suggests respiratory muscle fatigue.
As the episode becomes more severe, profuse diaphoresis occurs, with the diaphoresis presenting concomitantly with a rise in PCO2 and hypoventilation. In the most severe form of acute asthma, patients may struggle for air, act confused and agitated, and pull off their oxygen, stating, "I can’t breathe." These are signs of life-threatening hypoxia. With advanced hypercarbia, bradypnea, somnolence, and profuse diaphoresis may be present; almost no breath sounds may be heard; and the patient is willing to lie recumbent.
Nonpulmonary Manifestations
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 in the absence of an acute episode, such as during an outpatient visit between acute episodes. Turbinates may be erythematous or boggy. Polyps may be present.
Skin examination may reveal atopic dermatitis, eczema, or other manifestations of allergic skin conditions. Clubbing of the fingers is not a feature of asthma and indicates a need for more extensive evaluation and workup to exclude other conditions, such as cystic fibrosis.
Nocturnal Symptoms
A large percentage of patients with asthma experience nocturnal symptoms once or twice a month. Some patients only experience symptoms at night and have normal pulmonary function in the daytime. This is due, in part, to the exaggerated response to the normal circadian variation in airflow. Children with nocturnal asthma tend to cough after midnight and during the early hours of morning.
Bronchoconstriction is highest between the hours of 4:00 am and 6:00 am (the highest morbidity and mortality from asthma is observed during this time). These patients may have a more significant decrease in cortisol levels or increased vagal tone at night. Studies also show an increase in inflammation compared with controls and with patients with daytime asthma.
Staging
Asthma severity is defined as "the intensity of the disease process" prior to initiating therapy and helps in determining the initiation of therapy in a patient who is not on any controller medications. [1]
The severity of asthma is classified as the following:
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Intermittent,
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Mild persistent
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Moderate persistent
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Severe persistent
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 bronchial hyperresponsiveness (BHR; exercise or challenge testing) due to ongoing inflammation.
An important point to remember is that the presence of one severe feature is sufficient to diagnose severe persistent asthma. Also, the characteristics in this classification system are general and may overlap because asthma severity varies widely. A patient’s classification may change over time.
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Pathogenesis of asthma. Antigen presentation by the dendritic cell with the lymphocyte and cytokine response leading to airway inflammation and asthma symptoms.
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Asthma symptoms and severity. Recommended guidelines for determination of asthma severity based on clinical symptoms, exacerbations, and measurements of airway function. Adapted from Global Strategy for Asthma Management and Prevention: 2002 Workshop Report.
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Stepwise approach to pharmacological management of asthma based on asthma severity. Adapted from Global Strategy for Asthma Management and Prevention: 2002 Workshop Report.
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Asthma. High-resolution CT scan of the thorax obtained during inspiration in a patient with recurrent left lower lobe pneumonia shows a bronchial mucoepidermoid carcinoma (arrow).
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Asthma. High-resolution CT scan of the thorax obtained during expiration in a patient with recurrent left lower lobe pneumonia shows a bronchial mucoepidermoid carcinoma. Note the normal increase in right lung attenuation during expiration (right arrow). The left lung remains lucent, especially the upper lobe, secondary to bronchial obstruction with airtrapping (left upper arrow). The vasculature on the left is diminutive, secondary to reflex vasoconstriction. Left pleural thickening and abnormal linear opacities are noted in the left lower lobe; these are the result of prior episodes of postobstructive pneumonia (left lower arrow).
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High-resolution CT scan of the thorax obtained during inspiration demonstrates airtrapping in a patient with asthma. Inspiratory findings are normal.
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High-resolution CT scan of the thorax obtained during expiration demonstrates a mosaic pattern of lung attenuation in a patient with asthma. Lucent areas (arrows) represent areas of airtrapping (same patient as in the previous image).
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Posteroanterior chest radiograph demonstrates a pneumomediastinum in bronchial asthma. Mediastinal air is noted adjacent to the anteroposterior window and airtrapping extends to the neck, especially on the right side.
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Lateral chest radiograph demonstrates a pneumomediastinum in bronchial asthma. Air is noted anterior to the trachea (same patient as in the previous image).
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Asthma. High-resolution CT scan of the thorax obtained during inspiration in a patient with recurrent left lower lobe pneumonia shows a bronchial mucoepidermoid carcinoma (arrow).
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Asthma. High-resolution CT scan of the thorax obtained during expiration in a patient with recurrent left lower lobe pneumonia shows a bronchial mucoepidermoid carcinoma (same patient as in the previous image). Note the normal increase in right lung attenuation during expiration (right arrow). The left lung remains lucent, especially the upper lobe, secondary to bronchial obstruction with airtrapping (left upper arrow). The vasculature on the left is diminutive, secondary to reflex vasoconstriction. Left pleural thickening and abnormal linear opacities are noted in the left lower lobe; these are the result of prior episodes of postobstructive pneumonia (left lower arrow).
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Asthma. High-resolution CT scan of the thorax demonstrates mild bronchial thickening and dilatation in a patient with bilateral lung transplants and bronchial asthma.
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Asthma. High-resolution CT scan of the thorax demonstrates central bronchiectasis, a hallmark of allergic bronchopulmonary aspergillosis (right arrow), and the peripheral tree-in-bud appearance of centrilobular opacities (left arrow), which represent mucoid impaction of the small bronchioles.
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Asthma is characterized by chronic inflammation and asthma exacerbations, where an environmental trigger initiates inflammation, which makes it difficult to breathe. This video covers the pathophysiology of asthma, signs and symptoms, types, and treatment.
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- Overview
- Presentation
- DDx
- Workup
- Approach Considerations
- Blood and Sputum Eosinophils
- Serum Immunoglobulin E
- Arterial Blood Gas
- Periostin
- Pulse Oximetry Assessment
- Chest Radiography
- Chest CT Scanning
- Electrocardiography
- MRI
- Nuclear Imaging
- Allergy Skin Testing
- Pulmonary Function Testing
- Bronchoprovocation
- Peak Flow Monitoring
- Impulse Oscillometry
- Exhaled Nitric Oxide
- Sinus CT Scanning
- 24-Hour pH Monitoring
- Histologic Findings
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- Treatment
- Approach Considerations
- Environmental Control
- Allergen Immunotherapy
- Monoclonal Antibody Therapy
- Bronchial Thermoplasty
- Acute Exacerbation
- Asthma in Pregnancy
- Gastroesophageal Reflux Disease
- Sinusitis
- Nocturnal Asthma
- Long-Term Monitoring
- Functional Assessment of Airway Obstruction
- Perioperative Considerations
- Approach to Level of Activity
- Dietary Considerations
- Consultations
- Deterrence
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- Guidelines
- Medication
- Medication Summary
- Beta2-adrenergic agonist agents
- Anticholinergic Agents
- Anticholinergic agent combinations
- Corticosteroid, oral
- Long-acting beta2 agonists
- Beta2-Agonist/Corticosteroid Combinations
- Nonselective Phosphodiesterase Enzyme Inhibitors
- Mast cell stabilizers
- Corticosteroid, Inhalant
- Leukotriene Receptor Antagonist
- Monoclonal Antibodies, Anti-asthmatics
- Show All
- Questions & Answers
- Media Gallery
- References
