Diagnosis and management of asthma in older adults

INTRODUCTION — Asthma is common in adults over age 65 years [1,2] and it substantially reduces both psychologic and physical quality of life [2-5].

Some experts distinguish between older adults who previously had asthma in childhood or early adulthood and those whose asthma is newly diagnosed at a more advanced age. The diagnosis in the first category is usually reasonably clear. The diagnosis in the second category may be challenging due to the higher incidence of chronic obstructive pulmonary disease (COPD) and the longer list of differential diagnoses. We find these two categories helpful for the discussion of the disease but acknowledge their limitations. The clinical course may be more complex; for example, childhood asthma usually remits in adolescence but often reappears later in adulthood. The therapeutic approach is the same in both categories.

The clinical manifestations, evaluation, and management of asthma in older adults will be reviewed here. General topics on the evaluation, diagnosis, and management of asthma and COPD are discussed separately.

●(See "Asthma in adolescents and adults: Evaluation and diagnosis".)

●(See "An overview of asthma management".)

●(See "Chronic obstructive pulmonary disease: Diagnosis and staging".)

●(See "Stable COPD: Initial pharmacologic management".)

The United States Centers for Disease Control and Prevention (CDC) have identified older adults and persons with moderate to severe asthma as a potential at-risk group for severe illness in response to coronavirus disease 2019 (COVID-19; severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) [6]. Maintaining good asthma control and obtaining proper vaccination are essential to reduce this risk. Additional details are discussed separately.

●(See "An overview of asthma management", section on 'Advice related to COVID-19 pandemic'.)

EPIDEMIOLOGY — The prevalence of asthma in adults age 65 years and older is estimated at 4 to 8 percent [7,8] compared with a prevalence of approximately 8 percent in all adults [9]. A separate report estimated that over two million persons with asthma are aged ≥65 years, with this number expected to rise to more than five million by 2030 [7,10]. The epidemiology of asthma in general is discussed separately. (See "Epidemiology of asthma".)

RISK FACTORS AND TRIGGERS — Potential risk factors and triggers for asthma in older adults are generally similar to asthma triggers in other age groups [11-17]. It is worthwhile to ask older patients with asthma about triggers (table 1) because more than one-third of older patients with asthma report exercise-induced asthma symptoms; half report that animal contacts or exposure to dusts or fumes trigger their respiratory symptoms; and over two-thirds report seasonal worsening [2,18]. Asthma risk factors and asthma triggers are discussed in greater detail separately. (See "Risk factors for asthma" and "Trigger control to enhance asthma management".)

Specific risk factors and triggers that are common and well-studied in older populations include:

●Atopy – Despite a decline in prevalence of atopic symptoms, immunoglobulin E (IgE) levels, and positive allergen skin tests from childhood to older age [19], about one-fourth of older adults have at least one positive allergen skin test and about three-fourths of older patients with asthma are allergic to one or more common indoor allergens (eg, cockroach, cat, dog, mites) [5,20,21].

Older, as well as younger, adults with high levels of total IgE or specific IgE to cat or mite antigens are more likely to have bronchial hyperresponsiveness (BHR) or to develop BHR during two to three years of follow-up [22,23]. Older patients with asthma who have become sensitized to cockroach have more severe asthma and may experience a faster subsequent decline in lung function [24,25]. In Sweden and Finland, indoor dampness and mold growth are risk factors for adult-onset asthma [26,27].

●Tobacco use – Up to half of older people with a diagnosis of asthma are current or former smokers [2]. Tobacco smoking is not a major risk factor for development of asthma in older adults but can contribute to worsened control. Cigarette smoking is the major cause of chronic obstructive pulmonary disease (COPD) and emphysema but also increases production of IgE antibodies, bronchial responsiveness, and production of inflammatory markers in the sputum in older adults with asthma [28].

●Occupational, residential, and ambient air exposures – Cumulative airborne exposures may also increase the risk of asthma in older adults. For example, wood burning stoves and smoke from indoor use of biomass fuels (eg, wood, agricultural waste) are associated with the development of asthma in adults [12,26,29].

Increases in outdoor air pollution, especially particulate matter, have been associated with asthma exacerbations and increased hospital admissions for respiratory disorders [30-37]. In a study of the respiratory effects of air pollution in older adults, daily hospital admissions for asthma were highly associated with increases in NO₂ and SO₂ in the cool seasons and increases in black smoke year-around [38]. Ozone levels may also contribute to the development of asthma in older adults [29].

Among adults with asthma, about one-fourth have work-related asthma [39-41]. Exposure to dusts, gas, vapors, fumes, or sensitizers is also associated with asthma [41]. (See "Occupational asthma: Definitions, epidemiology, causes, and risk factors".)

●Medications – Certain medications used to treat hypertension, coronary heart disease, glaucoma, and arthritis (eg, topical or systemic beta blockers, aspirin, or nonsteroidal anti-inflammatory drugs [NSAIDs]) can exacerbate underlying asthma [42-44]. The risk of adult-onset asthma also increases among females taking postmenopausal hormone replacement therapy [45,46]. Discontinuing the triggering medications may lead to improved asthma control.

CLINICAL MANIFESTATIONS — The asthma symptoms of intermittent wheeze, cough, and chest tightness are no different in older persons than in younger persons, but older individuals are less likely to report dyspnea related to airflow limitation [47-49]. This may be the result of adaptation to the long-term presence of symptoms or lower health expectations [50].

Clues to the presence of asthma include symptoms of allergic disease (eg, nasal congestion, rhinorrhea, sneezing, and ocular itching) or nasal polyposis (eg, nasal congestion, anosmia, nonsteroidal anti-inflammatory drug [NSAID] sensitivity). Chronic cough may be suggestive of asthma in nonsmoking older patients [51]. Like most patients with asthma, older patients with asthma seen in the outpatient setting usually have a normal chest exam. Pale edematous nasal mucosa and/or the presence of nasal polyps increase the likelihood of concomitant asthma. (See "Asthma in adolescents and adults: Evaluation and diagnosis", section on 'Clinical features'.)

EVALUATION — The diagnosis of asthma generally requires pulmonary function testing to establish the presence of variable airflow obstruction. Pulmonary function testing, including spirometry with bronchodilator reversibility and methacholine challenge testing (MCT), is reliable in older adults. Home peak flow monitoring is not usually employed due to both measurement lability and unreliability in older patients as well as its relatively poor predictive power for the diagnosis of asthma [52-54]. (See "Peak expiratory flow monitoring in asthma".)

Chest radiographs are typically obtained to rule out alternative diagnoses. Laboratory studies, such as skin or serologic tests for allergy, are helpful in selected patients.

Pulmonary function testing — This section focuses on the use of pulmonary function tests (PFTs) in older adults; PFTs are discussed in more detail separately. (See "Overview of pulmonary function testing in adults" and "Pulmonary function testing in asthma".)

Spirometry with bronchodilator response — Since older patients often have few physical signs of asthma and have a high pretest probability of chronic obstructive pulmonary disease (COPD), spirometry before and after bronchodilator administration should be performed for all patients with a history of dyspnea, chronic cough, reduced exercise tolerance, or asthma-like symptoms [4,55-57]. However, because airflow limitation in asthma is intermittent and variable, the absence of airflow limitation on a given day does not rule out the diagnosis.

Despite concerns that frailty or decreased cognitive function would impair performance, the majority of older individuals are able to perform spirometry reliably with standard office spirometers [58-61]. For those who are highly physically frail, adequacy of spirometry can be less clear. There is a need to develop age-appropriate criteria regarding adequacy of spirometric test performance, as well as validation of alternative approaches, such as oscillometry, for measuring lung function in this population [62]. (See "Office spirometry", section on 'Equipment and hygiene'.)

Airflow obstruction is characterized by a reduced ratio of forced expiratory volume in one second (FEV₁) to forced vital capacity (FVC). Because this ratio normally declines with age, airflow limitation is defined by an FEV₁/FVC ratio below the lower limit of normal (ie, less than 5^th percentile or z-score <-1.645) using equations that normalize for age, sex, and height [63]. (See "Asthma in adolescents and adults: Evaluation and diagnosis", section on 'Diagnosis' and "Overview of pulmonary function testing in adults", section on 'Spirometry' and "Overview of pulmonary function testing in adults", section on 'Asthma'.)

While we advocate use of this definition for the diagnosis of all obstructive lung disease in older adults, a definition of COPD based on a fixed postbronchodilator FEV₁/FVC ratio <0.7 is still suggested by some guidelines [57].

Once the presence of airflow limitation has been identified by a reduced FEV₁/FVC ratio, the FEV₁ is used to determine the severity of the underlying obstruction (algorithm 1). Use of the recommended reference equations from the Global Lung function Initiative (GLI) are particularly helpful in older adults due to their broad applicability (the age range has been extended to 95 years compared with previous versions) [63,64]. Future work expanding the sample sizes for those over age 75 to 80 years may further improve reference values [64]. (See "Office spirometry", section on 'Interpretation' and "Selecting reference values for pulmonary function tests".)

Although the presence of airflow limitation increases suspicion for asthma, bronchodilator testing may greatly increase diagnostic certainty by ruling out other obstructive diseases generally characterized by more fixed obstruction (eg, COPD, bronchiolitis obliterans, bronchiectasis, and central airway obstruction). In patients with asthma, older age does not alter the acute response to inhaled bronchodilator (BD) drugs [65,66]. The probability of asthma is increased if the postbronchodilator FEV₁ increases by more than 10 percent of its predicted value [67]. Additionally, if the postbronchodilator FEV₁ and ratio improve from obstruction into the normal range, then the probability of asthma is greatly increased and COPD is by definition ruled out. (See "Overview of pulmonary function testing in adults", section on 'Post-bronchodilator'.)

Bronchoprovocation testing, if spirometry is normal — Bronchoprovocation testing, such as an MCT, can occasionally be helpful in the differential diagnosis of dyspnea and cough in older patients with normal spirometry who are not taking asthma medications [47,66,68]. Having wheezing or coughing due to allergens has been shown to be an independent predictor of a positive MCT in older adults with asthma [69]. With normal baseline spirometry, side effects from MCTs are rare, even in older persons.

A low provocative methacholine concentration causing a 20 percent decline in FEV₁ (PC-20) from the MCT increases the probability of asthma in patients with asthma-like symptoms. The prevalence of bronchial hyperresponsiveness (BHR) is higher in older compared with middle-aged adults, even after correcting for the baseline degree of airways obstruction, smoking status, and atopy [47]. Therefore, a PC-20 threshold of <4 mg/mL to define BHR in older patients may be more appropriate than the traditional <8 mg/mL. (See "Bronchoprovocation testing", section on 'Methacholine'.)

Assessment of atopy — We suggest assessing older adults with persistent asthma for sensitivity to indoor allergens with either allergen skin testing or serologic testing. Conversely, we do not typically perform such testing in mild or easily controlled disease. (See "Overview of skin testing for IgE-mediated allergic disease" and "Overview of in vitro allergy tests".)

Among patients with symptoms of exertional dyspnea, cough, or wheeze, the presence of atopy makes asthma more likely than COPD [70]. In one study, the rate of atopy was 37 percent among patients with asthma and 8 percent among those with COPD [70]. Although the atopy rate of the general population declines from middle age (30 percent) to older age (8 percent) [19], about three-fourths of older patients with asthma have a positive allergen skin test to aeroallergens, and about one-fourth of those with a cat or dog become sensitized to their pet [5]. In another study, half of older patients with asthma living in urban areas were sensitized to cockroach antigen, and this sensitivity was associated with more severe airways obstruction and hyperinflation [24]. In addition, knowledge of the allergens to which a patient is sensitized can help guide mitigation efforts.

Imaging — The chest radiograph is almost always normal in patients with asthma. However, a chest radiograph is indicated when evaluating older adults for symptoms suggestive of new-onset asthma to exclude alternative diagnoses. (See "Asthma in adolescents and adults: Evaluation and diagnosis", section on 'Imaging'.)

DIAGNOSIS — Confirmation of the diagnosis of asthma in older adults is based on the presence of respiratory symptoms suggestive of asthma and the demonstration of variable expiratory airflow obstruction on pulmonary function testing in the absence of competing diagnoses. Variability in airflow obstruction may be apparent from measurements made at different points in time, in response to an asthma trigger, or after asthma therapy. As an example, a patient's forced expiratory volume in one second (FEV₁) might vary from one visit to the next, before and after inhalation of methacholine, or before and after inhaled bronchodilator. (See "Asthma in adolescents and adults: Evaluation and diagnosis" and "Pulmonary function testing in asthma".)

DIFFERENTIAL DIAGNOSIS — The differential diagnosis of intermittent respiratory symptoms in older adults in many cases is more difficult than in younger adults due to the higher prevalence of nonasthma conditions among older patients with dyspnea (table 2).

The three most common causes of chronic or intermittent dyspnea in older adults are chronic obstructive pulmonary disease (COPD) and emphysema, heart failure (HF), and asthma [71]. (See "Approach to the patient with dyspnea", section on 'Initial testing in chronic dyspnea'.)

COPD and emphysema versus asthma — Differentiating COPD and emphysema from asthma can be difficult; COPD and asthma may also coexist in some patients. The pretest probability of COPD and emphysema in a patient with a substantial (particularly past) smoking history is much higher than for asthma; in contrast, atopic symptoms and allergic rhinitis are suspicious for asthma.

On pulmonary function testing, airflow limitation that is significantly or completely reversible with inhaled bronchodilator favors a diagnosis of asthma. However, many patients with COPD have significant reversibility to inhaled bronchodilators (BDs) and some patients with emphysema by computed tomography (CT) scan may have complete reversibility and/or no airflow limitation. In current or former smokers with airflow limitation but without a large BD response, a low diffusing capacity (DLCO) strongly suggests COPD and emphysema rather than asthma [72,73]. Similarly, former or current smokers who carry the diagnosis of asthma but have a reduced DLCO, hyperinflation on their chest radiograph, or hyperinflation on lung volume testing may benefit from cross-sectional imaging to evaluate for emphysema [74]. (See "Chronic obstructive pulmonary disease: Diagnosis and staging".)

Asthma and COPD overlap — While a formal definition has not been agreed upon, asthma and COPD overlap is described as being "characterized by persistent airflow limitation with several features usually associated with asthma and several features usually associated with COPD" [75]. Recognizing such patients may help guide therapeutic choices and potentially identify the need for a comprehensive geriatric assessment. (See "Asthma and COPD overlap (ACO)".)

Investigations using standard epidemiologic definitions of obstructive airways disease and data on a large sample of participants from the Medical Expenditure Panel Survey (United States) have shown that a substantial proportion of persons aged 65 to 85 years (37 percent) meet the description of asthma-COPD overlap [76]. Furthermore, compared with either COPD or asthma alone, asthma-COPD overlap was significantly associated with increased mobility impairment and health care utilization, suggesting that these patients may particularly benefit from comprehensive geriatric assessment and management. (See 'Monitoring the geriatric patient' below.)

Heart failure versus asthma — The differentiation of heart failure (HF) from asthma in the ambulatory setting may be challenging, particularly when the disease is mild. It is also not uncommon for older patients to suffer from both asthma and heart failure concomitantly. Objective evidence of elevated jugular venous pressure, S3, peripheral edema, and vascular congestion on chest radiograph all increase the probability of HF. Systolic dysfunction on echocardiography makes the diagnosis of HF; signs of diastolic dysfunction (eg, increased E/A ratio) on echocardiography are less definitive as they can be positive in states of left ventricular underfilling due to low preload pressure, for example, from COPD and emphysema [77], among other diagnoses. Evidence of airflow obstruction on spirometry defines obstructive airways disease. (See 'Spirometry with bronchodilator response' above.)

Cardiovascular disease in ambulatory older persons usually causes only a mild reduction in the forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC) of approximately 0.1 to 0.3 liters [78]. Substantial airflow limitation in a patient presenting to the emergency department or in the hospital is much more likely due to asthma or COPD than HF [79]. (See "Determining the etiology and severity of heart failure or cardiomyopathy".)

In patients with acute dyspnea, chest radiograph and measurement of B-type natriuretic peptide (BNP) may also help differentiate these entities. (See "Approach to the adult with dyspnea in the emergency department", section on 'Plain chest radiograph'.)

Other — Restrictive lung disease, pulmonary vascular disease, bronchiectasis, and upper airway obstruction can also present with symptoms that mimic asthma (table 2). Consideration of these diseases in the context of a potential diagnosis of asthma is discussed separately. (See "Asthma in adolescents and adults: Evaluation and diagnosis", section on 'Differential diagnosis'.)

TREATMENT — Successful management of asthma in older adults is based on four essential components (education, control of asthma triggers, monitoring, and pharmacologic therapy) used for management of asthma at all ages. The comments below outline considerations that specifically pertain to older adults; a general approach to asthma management is provided separately. (See "An overview of asthma management".)

Patient education and adherence — Asthma education includes communicating the features and mechanism of asthma, the appropriate role and use of asthma medications, and measures to treat and prevent symptoms. As with younger patients, a written asthma action plan is important to achieve optimal care [80-82]. (See "Asthma education and self-management".)

Some older patients have difficulty learning correct inhaler technique, which is essential for optimal efficacy of inhaled medications. Observation of the patient’s technique is a key step in ensuring that the patient is using inhalers properly. Cognitive impairment, which can be established by a number of screening tests, predicts difficulty learning and retaining inhaler technique [83-88]. Alternatively, simply requiring patients to "teach back" inhaler technique may identify those with difficulty performing multistep commands [87]. Cognitive impairment often leads to uncoordinated "press and breathe" use of inhalers as well as nonadherence [87]. (See "Mental status scales to evaluate cognition" and "Evaluation of cognitive impairment and dementia".)

Use of a hydrofluoroalkane (HFA) pressurized metered dose inhaler (MDI) with a valved holding chamber, a breath-actuated dry powder inhaler, or a nebulizer may improve medication delivery when technique is suboptimal [89,90]. (See "Delivery of inhaled medication in adults" and "The use of inhaler devices in adults".)

Other health conditions may also impact asthma medication adherence, such as arthritis leading to difficulty in the handling of inhalers, particularly metered dose inhalers (MDIs) [91,92]. Further, older adults have lower inspiratory flow rates and may not be able to achieve the higher inspiratory flow rates required for some dry powder inhalers [91]. The use of an inspiratory flow meter may help in determining the appropriate inhaler type [93].

Control of asthma triggers — Allergen avoidance and mitigation (efforts to reduce indoor allergen levels) is beneficial in children and is also recommended in adults, including older adults (table 3). (See "Trigger control to enhance asthma management".)

Cigarette smoke is an airway irritant, and smoking cessation is associated with improvement in lung function [94]. (See "Trigger control to enhance asthma management", section on 'Irritants (including cigarette smoke)' and "Overview of smoking cessation management in adults" and "Pharmacotherapy for smoking cessation in adults".)

Infectious triggers can be mitigated through reducing exposure (eg, handwashing, judicious face mask use) and recommended vaccinations for older adults (eg, influenza, pneumococcus, and COVID-19). (See "Pneumococcal vaccination in adults" and "Seasonal influenza vaccination in adults" and "COVID-19: Vaccines".)

Monitoring the geriatric patient — Among older persons, apparent changes in asthma control may result from comorbidities, polypharmacy, psychosocial changes, or geriatric health conditions; conversely, other changes in clinical status may be consequences of under-recognized worsening of asthma control.

Older persons often require a comprehensive geriatric assessment due to the their complex clinical presentations [95]. Advancing age is associated with increased multimorbidity (62 percent of older Americans have two or more chronic conditions), medication-related adverse effects (20 to 30 percent of older Americans use medications listed in drugs-to-avoid lists), psychosocial factors (less education, sedentary lifestyle, social isolation), geriatric health conditions (cognitive and sensory impairments, falls, incontinence, weight loss, dizziness, etc), and reduced symptom awareness [47-50,95-101].

Training to estimate peak flow, followed by peak flow monitoring feedback and motivational interviewing, may be able to improve underperception of airflow obstruction in older patients [102].

Otherwise, routine monitoring of asthma control, lung function, exacerbations, inhaler technique, adherence, medication adverse effects, quality of life, and patient satisfaction with care is similar to that in other adult patients. (See "An overview of asthma management", section on 'Follow-up monitoring'.)

Pharmacologic management — The National Asthma Education and Prevention Program (NAEPP) and the Global Initiative for Asthma (GINA) recommend starting with a determination of asthma severity to guide initial therapy (table 4) [103,104]. The goal is to control symptoms quickly and subsequently adjust therapy in a stepwise fashion as symptoms and pulmonary function require. All patients should have access to a "quick-relief" fast-acting beta-agonist. In addition, patients with frequent symptoms or exacerbations are candidates for maintenance therapies, of which inhaled glucocorticoids are the initial preferred agent. (See "An overview of asthma management", section on 'Initiating pharmacologic treatment'.)

Asthma therapy is adjusted using a stepwise approach (table 4) based upon an assessment of asthma control (table 5) and any adverse effects of medications. The degree of asthma control is determined by the most severe indicator of impairment (table 5). Assessing asthma control is discussed in more detail separately. (See "An overview of asthma management", section on 'Adjusting controller medication'.)

When asthma is not well-controlled, possible causes of poor adherence should first be considered, such as the cost of the inhalers, difficulty using the inhaler, increased exposure to triggers, depression, or worries about steroid side effects [105-107]. (See "Enhancing patient adherence to asthma therapy", section on 'Reasons for nonadherence'.)

In general, management is not different for older versus younger adults. However, multiple combinations of agents are reasonable for different tiers of therapy (table 4), some of which may be more useful in older patients. Specific considerations in older adults include:

●Inhaled glucocorticoid side effects – In older adults, we generally prefer to add a long-acting beta-agonist (LABA), tiotropium, or an antileukotriene agent as step-up therapy while maintaining a lower dose of inhaled glucocorticoids (GCs) to reduce the risk of inhaled GC side effects (table 4). Use of this approach is particularly helpful in those with certain common comorbidities (eg, hoarseness, osteoporosis, or glaucoma).

High daily doses of inhaled GCs may decrease bone mineral density and increase the risk of fracture, although data are conflicting [108-110]. To decrease the effects of corticosteroids on bone resorption, patients should be encouraged to exercise (if possible), avoid excess alcohol intake, and obtain a healthy dietary intake of calcium and vitamin D [111]. Older adults on chronic therapy with inhaled GCs who have a moderate risk of osteoporosis should undergo bone density measurement to assess the need for preventive therapy. (See "Screening for osteoporosis in postmenopausal women and men" and "Prevention and treatment of glucocorticoid-induced osteoporosis", section on 'General measures' and "Major side effects of inhaled glucocorticoids".)

In addition to effects on bone density, inhaled GCs are a common cause of oral candidiasis and hoarseness in older adults, which can be mitigated by careful oral rinsing after use of the inhaled GC. For hoarseness, sometimes use of a smaller particle size agent, such as beclomethasone HFA rather than a fluticasone dry powder inhaler, can reduce laryngeal deposition and dysphonia. (See "Major side effects of inhaled glucocorticoids".)

●Cardiovascular effects of beta-agonists – Although beta-agonists can increase heart rate and reduce serum potassium concentration, they have generally been found to be safe in older adults. For patients with known cardiovascular disease, especially atrial fibrillation, we prefer to try a higher dose of inhaled GCs or an add-on antileukotriene agent to achieve control before starting a LABA (table 4).

Among 12,090 patients age 55 years or older with chronic obstructive pulmonary disease (COPD), beta-agonists were not associated with an increase in the risk of fatal or nonfatal myocardial infarction [112]. Except for formoterol administration as part of single maintenance and reliever therapy (SMART), fast-acting beta-agonists should be used only when needed. Scheduled dosing does not confer additional benefit. (See "Treatment of moderate persistent asthma in adolescents and adults", section on 'Reliever medications'.)

The safety of LABAs in older adults with asthma has not been directly assessed in large groups of patients [113]. The most reassuring data regarding cardiovascular safety of LABAs come from studies of older adults with COPD. As an example, patients with COPD experience no greater morbidity when using salmeterol with fluticasone compared with fluticasone alone. (See "Management of the patient with COPD and cardiovascular disease", section on 'Long-acting beta-agonists' and "Management of the patient with COPD and cardiovascular disease", section on 'Combination inhaled bronchodilators plus glucocorticoid'.)

●Reducing oral glucocorticoid exposure – Chronic prednisone therapy has multiple potential side effects in older patients, especially older females, including hip and vertebral fractures, cataracts, poor glycemic control, and herpes zoster [108]. We prefer short courses (five to seven days) of oral GCs and avoidance of long-term therapy except as a last resort. (See "Major side effects of systemic glucocorticoids" and "Screening for osteoporosis in postmenopausal women and men" and "Prevention and treatment of glucocorticoid-induced osteoporosis" and "Acute exacerbations of asthma in adults: Home and office management" and "Acute exacerbations of asthma in adults: Emergency department and inpatient management", section on 'Systemic glucocorticoids'.)

●Efficacy of biologic therapies in the older population – Anti-IgE, anti-interleukin (IL) 4, anti-IL5/anti-IL5 receptor, and anti-thymic stromal lymphopoietin biologic therapies have been found to reduce asthma exacerbations by approximately 50 percent in patients with poorly controlled asthma despite maximal inhaled therapies. (See "Treatment of severe asthma in adolescents and adults", section on 'Persistently uncontrolled asthma' and "Anti-IgE therapy".)

Although these trials included some patients between the ages of 65 and 75 years, most patients studied were middle-aged adults, making the risks and benefits less certain in the older population. Mechanistically, there are physiologic changes in the immune system of older persons that could impact biologic agent effectiveness. For example, age-associated changes in eosinophils include decreased degranulation in response to IL-5 stimulation, and sputum cellularity is generally more neutrophilic in older versus younger patients with asthma [114]. The implications of these changes remain uncertain.

Anti-IgE therapy, the oldest of the biologic agents, has been studied most extensively and appears to have similar efficacy in older and younger populations. One study found that patients age 50 years or older, compared with younger patients, experienced a comparable reduction in exacerbation rate (69 versus 75 percent), slightly less of an improvement in asthma symptoms and nocturnal awakenings (68 and 73 percent in the older versus 79 and 82 percent in the younger patients), and a similar improvement in lung function [115]. There was a higher rate of discontinuation of omalizumab therapy in older patients (21 versus 11 percent). In a pooled analysis of placebo-controlled trials, participants age 50 years and older on anti-IgE therapy showed reduced risk of asthma exacerbations, improved asthma symptom scores, and reduced rescue medication use compared with placebo [116].

The adverse effects associated with omalizumab have not been specifically examined in older adults. Typical adverse effects of anti-IgE therapy are discussed separately. (See "Anti-IgE therapy", section on 'Adverse effects'.)

Specific data on the benefits and adverse effects of other biologic agents in older populations are lacking, but they are under active investigation.

●Theophylline toxicity – Theophylline is not suggested for treatment of asthma in most older adults due to variable metabolism and multiple medication interactions. Chronic overmedication with theophylline causes major toxic events, including death [117]. (See "Theophylline poisoning" and "Theophylline use in asthma", section on 'Safe use of theophylline'.)

PROGNOSIS — Adult-onset asthma is more likely to become life-long and to have morbidity when compared with asthma beginning in childhood [11,118]. Compared with younger adults with asthma, older adults have more hospitalizations, more comorbidities, and poorer lung function [118-121]. In a large United States database examined from 2006 to 2008, older adults with asthma had a fivefold increased risk of overall mortality compared with younger adults with asthma even after adjustment for comorbidities [121]. However, a six-year observational study of 4756 patients with asthma, The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study, reported that the hospitalization rate was actually lower among the cohort age 65 years and older than the younger cohort [80]. The explanation for the lower hospitalization rate may have been more aggressive asthma care among the older adults in this supervised population, suggesting that optimizing asthma care has the potential to improve outcomes.

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Asthma in adolescents and adults" and "Society guideline links: Severe asthma in adolescents and adults".)

SUMMARY AND RECOMMENDATIONS

●Epidemiology – Asthma is common in adults over age 65 years. Some patients will have had asthma since childhood and others may have developed asthma as adults. Asthma is less likely to resolve spontaneously in older adults. (See 'Epidemiology' above.)

●Risk factors and triggers – Atopy remains a common finding on skin testing in older adults. Smoking, animal dander, and occupational exposures are common asthma triggers in this population. (See 'Risk factors and triggers' above and 'Assessment of atopy' above and "Trigger control to enhance asthma management".)

●Evaluation, diagnosis, and differential diagnosis

•Spirometry, bronchodilator response, and methacholine responsiveness are accurate in most older adults. (See 'Spirometry with bronchodilator response' above and 'Bronchoprovocation testing, if spirometry is normal' above and "Asthma in adolescents and adults: Evaluation and diagnosis", section on 'Diagnosis'.)

•Distinguishing asthma from chronic obstructive pulmonary disease (COPD) is a common diagnostic challenge in older patients with intermittent dyspnea. Diffusing capacity, lung volume measurement, and chest CT (in selected patients) may help to differentiate these conditions. Asthma and COPD overlap is not uncommon, although definitions vary. (See 'Pulmonary function testing' above and 'COPD and emphysema versus asthma' above and 'Asthma and COPD overlap' above and "Asthma and COPD overlap (ACO)".)

●Differences in the management of asthma in older persons – Successful management of asthma in all patients is based on four essential components (education, control of asthma triggers, monitoring, and pharmacologic therapy). (See "An overview of asthma management".)

The comments below outline considerations that specifically pertain to older adults:

•Inhaler technique and adherence – Some older patients have difficulty learning correct inhaler technique or develop difficulties with technique or adherence due to cognitive impairment. Older adults also may not be able to activate some dry powder inhalers due to low inspiratory flow rates. (See 'Patient education and adherence' above.)

•Vaccination against respiratory illnesses – Older persons with asthma are at increased risk for poor outcomes after infection with influenza, pneumococcus, and COVID-19 and should receive vaccination against these pathogens. (See 'Control of asthma triggers' above.)

•Monitoring the geriatric patient – Monitoring in older persons frequently includes a comprehensive geriatric assessment due to multiple comorbid conditions, deconditioning, nutritional status, and/or polypharmacy. (See 'Monitoring the geriatric patient' above.)

•Pharmacologic management – The pharmacologic management of asthma in older persons should be in concordance with international guidelines, which advise initial therapy based on asthma severity (table 4) followed by a stepwise adjustment (table 4) based on asthma control (table 5). (See 'Pharmacologic management' above.)

Special considerations in older patients include:

-In older patients with poorly controlled asthma, we generally prefer to add a long-acting beta-agonist (LABA), tiotropium, or an antileukotriene agent as step-up therapy while maintaining a lower dose of inhaled glucocorticoids (GCs). This strategy reduces the risk of inhaled GC side effects, some of which are more common in older persons. Use of this approach is particularly helpful in those with certain comorbidities (eg, hoarseness, osteoporosis, or glaucoma). (See 'Pharmacologic management' above and "Major side effects of inhaled glucocorticoids".)

-For older patients with poorly controlled asthma and known cardiovascular disease, especially atrial fibrillation, we prefer to use an add-on leukotriene or a moderate dose of inhaled GCs to achieve control before starting a LABA.

-We minimize exposure to oral GCs and do not use theophylline in older patients due to an increased risk of adverse effects.

-While anti-IgE therapy (omalizumab) appears to have comparable efficacy in older adults who meet the usual indications, the specific risks and benefits of other biologic agents in the older population require further study.

ACKNOWLEDGMENTS — The UpToDate editorial staff acknowledges Paul Enright, MD, R Graham Barr, MD, DrPH, and Carlos A Vaz Fragoso, MD, who contributed to earlier versions of this topic review.