The goal of this article is to inform readers of the common and uncommon signs and symptoms of asthma. After completion of this article, readers should have a firm understanding of the symptoms and presentation leading to a diagnosis of asthma.
Key points
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The four main symptoms of asthma are wheezing, cough, chest tightness, and dyspnea.
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A thorough history taking is essential—personal, family, and social histories must be obtained.
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Infants and preschoolers must be diagnosed based on presentation, history, and physical examination because objective measures cannot easily be used.
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Asthma in the elderly is underdiagnosed and often compounded by comorbidities.
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The physical examination can help distinguish the severity of the asthma exacerbation.
Overview
Asthma is a common diagnosis in both outpatient and emergency department settings. It has a varied presentation between patients and between each exacerbation. Hence, understanding the common symptoms and presentations is essential to correctly diagnosing this disease.
This article discusses the symptoms of asthma, age-related key points, variables and differential diagnoses, the classification of acute asthma attacks, physical examination essentials, and risk factors for development and death from this disease process.
Overview
Asthma is a common diagnosis in both outpatient and emergency department settings. It has a varied presentation between patients and between each exacerbation. Hence, understanding the common symptoms and presentations is essential to correctly diagnosing this disease.
This article discusses the symptoms of asthma, age-related key points, variables and differential diagnoses, the classification of acute asthma attacks, physical examination essentials, and risk factors for development and death from this disease process.
Symptoms
Asthma is defined as a reversible airway obstruction that presents with some combination of wheezing, dyspnea, airway hyperresponsiveness, cough, and mucus hypersecretion. The 4 most common presenting symptoms are wheezing, cough, shortness of breath, and a subjective sensation of chest tightness. Although asthma can have a variable presentation, this is the main constellation of symptoms. One or more of these symptoms are present during an asthma attack. Not only does the presentation vary between people but also a single patient may have extreme variation between each exacerbation.
Asthma is often described as a chronic disease with intermittent symptoms and acute exacerbations. It is reported, however, that up to 27% of people with asthma have daily symptoms. Although asthma can occur in any age group, in Western countries it is known as the most common chronic disease of childhood. Classically, younger patients present with recurrent wheezing and/or coughing episodes that may or may not be accompanied by chest tightness or dyspnea ; 80% of patients have a slow onset of asthma symptoms with progressive deterioration over a period of 6 or more hours.
Because this presentation has a broad differential diagnosis, patients’ exposure to allergens or triggers and their response to bronchodilators are of key importance. These topics are discussed further by Ferguson and colleagues elsewhere in this issue. See Table 1 for a concise summary.
| Common symptoms |
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| Common physical examination findings |
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Wheezing
Wheezing, most commonly on expiration, is the hallmark symptom of an acute asthma exacerbation. Wheezing is neither sensitive nor specific, however, and the presence of wheezing is not necessary in order to diagnose asthma. Additionally, there are multiple other disease processes that may present with wheezing.
Wheezing is defined as a musical, high-pitched, whistling sound produced by airflow turbulence. The sound occurs due to airflow passing through narrowed bronchioles. Wheezing may not carry an obvious pattern during the respiratory cycle but rather is noted at various, seemingly random, points during respiration. Wheezing varies in tone and duration over time. The characteristics of the wheeze often clue a physician to the degree of exacerbation. A mild exacerbation presents with only end-expiratory wheezing. A severe exacerbation usually has both inspiratory and expiratory wheezing present. In its most severe form, patients may have an absence, or loss, of wheezing, which denotes a significantly narrowed airway with limited airflow. This is indicative of impending respiratory failure and respiratory muscle fatigue.
Should a patient present with wheezing, it is essential to consider diagnoses other than asthma by combining symptoms, physical examination, and diagnostic testing, such as spirometry, methacholine challenge, and/or a bronchodilator trial. Chapter 5 discusses diagnostic testing in further details. If wheezing clears with cough, for example, a secretion issue may be suspected. If a wheeze is monophasic and begins and ends consistently at the same point of each respiratory cycle, local bronchial narrowing due to foreign body or bronchogenic carcinoma should be considered.
Cough and Mucus Production
Cough is another common presenting symptom of asthma. Many patients emphasize that their cough is present nocturnally, especially from midnight until the early morning hours, and describe it as nonproductive. If sputum is present, it is usually clear mucoid or pale yellow in appearance. In the pediatric population, the frequency of coughing is thought related to the amount of neutrophils present in the sputum, suggesting an infectious cause in this group of patients. Because cough is occasionally the only symptom, chronic cough in adults should prompt a work-up for asthma, especially if symptoms are seasonal or if the cough presents after trigger exposure. At times, cough is the only symptom and is described in the literature as cough-variant asthma or cough-equivalent asthma; this form is rarely accompanied by wheezing or dyspnea. There is also exercise-induced asthma, which often presents with cough. These specific forms of asthma are discussed by Ryan and colleagues elsewhere in this issue.
Although discussed less in the literature, the presence of increased mucus production can also indicate asthma when combined with other symptoms. Up to 9% of patients have profuse sputum production during attacks due to impairment of mucociliary clearance. When present, this often signifies poor asthma control.
Chest Tightness
A subjective symptom that is commonly described is chest tightness. Although this can be present in any form of asthma, it is often seen in exercise-induced and nocturnal asthma. Often it is referred to as a generalized chest pain, a sensation of chest congestion, or difficulty with deep inspiration. Patients describe it as a band-like constriction or a heavy weight, rarely a sharp pain. This, too, may be the only symptom or may be part of a constellation of symptoms. Unfortunately, this complaint is not specific and is seen in multiple cardiac, pulmonary, and gastrointestinal conditions. Therefore, an isolated symptom of chest tightness must be thoroughly worked up for other serious and life-threatening conditions prior to arriving at the conclusion of asthma.
Dyspnea
Dyspnea is a subjective sensation of shortness of breath. Often patients describe this as “difficulty breathing.” Again, dyspnea does not imply asthma and must be evaluated in a larger context.
History Taking
Given the nonspecific signs of asthma (discussed previously), it is essential to take a thorough history when patients present with symptoms. The discussion should focus on personal, family, and social histories. Clinical symptoms should be described by the patient or parent in terms of intensity, duration, frequency, environmental exposure, nocturnal frequency, and seasonal components. A patient’s personal history is of utmost importance. Indicators in a patient’s history that make asthma more likely include a history of atopy or dry cough. Allergy is a trigger in 60% to 90% of children and in half of adults. The physician should elucidate a patient’s exacerbation history—What are the usual prodromal signs and symptoms? How quickly did this attack come on? Are there any associated illnesses or comorbidities? How many attacks, emergency room visits, and hospitalizations have there been in the past year? Has an attack ever required intubation?
Many patients describe a personal or family history that includes asthma, allergies, sinusitis, rhinitis, and/or eczema, indicating a genetic predisposition to atopy and likely atopic component to the asthma diagnosis. Nasal polyps and/or a history of aspirin sensitivity may occur with asthma. This is also known as aspirin-exacerbated respiratory disease (AERD). Social history is important to determine a patient’s contact with possible triggers, whether environmental, such as tobacco exposure, or work related. Elsewhere in this issue, Ferguson and his colleagues discusses asthma triggers in greater detail.
Asthma by age group
Infants/Preschoolers
Infants and preschoolers are particularly challenging to evaluate and work-up because they are unable to participate in subjective questioning or diagnostic studies. Despite this, preschool age is commonly the first time that patients have their first asthma attack. The diagnosis must be made on symptoms, physical examination, risk factors, and response to treatment because objective measures cannot be used. The pattern of their disease usually includes brief, recurrent exacerbations of coughing and wheezing. On presentation, this age group usually has cough, wheezing, and prolonged expiration. In addition, they frequently feel anxious. Older children often complain of chest tightness or recurrent chest congestion.
There are a few additional presentations that should clue physicians to the possibility of an asthma diagnosis in this age group. The children often have nonspecific symptoms that are diagnosed as other diseases, such as recurrent bronchitis or bronchiolitis, recurrent pneumonia, or croup. Parents often describe persistent cough associated with colds and viruses. Most children who have chronic or recurrent bronchitis or pneumonia have asthma as an underlying diagnosis. In school-aged children, asthma exacerbations peak in early September and are least common in the summer months.
It is thought that in young children, up to 85% of wheezing episodes are triggered by viral infections, suggesting causation for the overlap of the disease entities discussed previously. Most commonly, respiratory syncytial virus and rhinovirus are implicated as viral triggers. A strong association was found between rhinovirus-associated wheezing requiring hospitalization during the first 2 years of life and childhood asthma. The risk of developing childhood asthma in this population was 4-fold the risk compared with children presenting with other viral illnesses. Unlike older children and adolescents, preschoolers have less impairment from their disease process.
The probability of asthma as the primary diagnosis in pediatric patients increases if they present with more than 1 of the 4 common symptoms of asthma. From the history, it should be gathered whether the current symptoms are separate from a recent cold or infection, if the symptoms are frequent or recurrent, if they are worse at night or in the early morning, and if they are associated with exercise or known triggers. Parents may describe severe episodes of wheezing or dyspnea that began after 1 year of age and/or a chronic cough. All of these make the diagnosis of asthma more probable. Common comorbidities in pediatric patients with asthma include gastroesophageal reflux disease (GERD), rhinosinusitis, dysfunctional breathing, obesity, and food allergy. Asthma symptoms in the face of any of these diagnoses should trigger a suspicion for asthma.
There are 3 wheezing phenotypes that have been described in the preschool-aged population. These have been used to help determine if asthma will be present later in life. The early transient phenotype begins in the first 3 years of life and resolves by age 6. Persistent wheezers also initiate wheezing episodes before age 3, but these continue to persist at age 6. Late-onset wheezing does not begin until a patient is between 3 and 6 years old. Transient early wheezers often outgrow their symptoms. Those with persistent or late-onset wheezing are more likely to have symptoms into adolescence and adulthood. If recurrent wheezing is present in the first 3 years of life, a child is at a 4.7 times greater risk of developing asthma. If the wheezing persists or is present in years 4 through 6, the risk is 15 times that of the general population.
Elderly
Asthma in the elderly is more common than many physicians realize, and being aware of the possibility in this age group is essential to providing appropriate care. Whereas asthma is frequently diagnosed in childhood, it is often underdiagnosed and undertreated in the elderly (age >65) population. After the age group birth to 4 years old, patients over 65 have the highest rate of office or emergency department visits for asthma. Difficulties of diagnosis in this age group are not only their physiologic age-related changes in respiratory and immune status but also their decreased awareness of subjective symptoms, such as dyspnea, making a delay in diagnosis common. Symptoms are the same as in younger patients, but the differential diagnosis is much broader for an elderly population (discussed later). Additionally, asthma presents in the face of other comorbidities, and the symptoms associated with asthma often are swept into another diagnosis. Another difficult differentiation lies between asthma and chronic obstructive pulmonary disease (COPD). There are many patients with both diagnoses and asthma activity is increased in patients with COPD. The preferred way to differentiate between an asthma and COPD exacerbation is not symptoms or presentation but via diagnostic testing. See Table 2 for a concise summary.
