Asthma in the elderly

Epidemiology

Asthma may be first diagnosed at any age and is common in the elderly. A variety of population-based studies[1–3] have shown that the prevalence of asthma in the elderly is similar to that in other adult age groups, i.e., 4.5-8%. In one study,4 40% of the elderly population attending ambulatory care centres in hospitals or living in subsidized nursing homes and lodges had asthma, emphasizing that it may occur with and be mistaken for such disorders as cardiac failure and COPD; in those with long-standing asthma, the disease may be difficult to distinguish from COPD.5

Although in some elderly patients asthma may have been present earlier in life, in at least half it is recently acquired.5 An incidence study6 demonstrated a rate of newly diagnosed asthma of 0.1% a year in those over 65 years of age. Although atopy is considered to be less common in older adults, sensitization to cat allergen has been associated with late-onset asthma,7 and allergy, often to household dust mites, was identified in 72% of elderly patients with late-onset asthma in Italy.8 The use of replacement estrogen in women may increase the risk of late-onset asthma.9

Asthma in the elderly, more so than in younger populations, may be associated with the use of medications including ASA, nonsteroidal anti-inflammatory drugs (NSAIDs) and adrenergic-blocking agents, including topical preparations. There is also anecdotal evidence of the association of asthma with other agents.10

Elderly patients may have more severe asthma and may be more prone to exacerbations and the need for urgent treatment and hospital admission,11 possibly because of underdiagnosis, undertreatment1 or poor perception of symptoms.[12, 13]

Diagnosis

As noted, asthma may be difficult to diagnose in the elderly because of misconceptions about its prevalence and also because older patients may have diseases and disorders that mask the classic features of asthma. Spirometry before and after using a bronchodilator should be an essential investigation in an elderly patient with otherwise unexplained dyspnea, wheeze or cough. Although spirometry may be difficult to perform in the elderly, at least one report indicates that it is feasible even in confused patients.4 Unfortunately, at least some elderly people with asthma will show airway obstruction without a response to β₂-agonist and, in some instances, this may reflect irreversible obstructive lung disease due to longstanding, unrecognized and untreated disease.5

Treatment

As in any age group, treatment must begin with the advice to avoid asthma-inducing agents. In the elderly patient with asthma, it is particularly important to take a careful medication history. Use of self-prescribed ASA has become common and may go unrecognized. ASA and NSAIDs are commonly prescribed in the elderly and may cause late-onset asthma. Oral and topical β-adrenergic blocking agents14 and other anti-arrhythmic agents, including verapamil,10 and others with acknowledged β-blocker potential can exacerbate or cause asthma in those who are predisposed to the disease.15 Whenever possible, medications that might induce or aggravate asthma should be withdrawn. In other respects, the management of asthma in the elderly does not differ from that recommended for other age group, although particular care should be taken in the selection of and instruction in the use of inhaler devices.[16, 17]

Attention should be paid to the prevention of osteoporosis in elderly patients who require oral glucocorticosteroid therapy. The use of estrogen replacement therapy in postmenopausal women who require oral glucocorticosteroids is generally recommended although this advice has been challenged in a report linking estrogen use to an increased risk of developing asthma.8 Etidronate used cyclically with vitamin D and calcium supplementation has also been shown to improve bone density in older patients requiring prolonged oral corticosteroid therapy for asthma.18

Recommendations

• A diagnosis of asthma should be more widely considered in elderly patients with dyspnea, wheezing or nocturnal cough (level III).

• Investigation to determine exposure to environmental and other asthma-inducing factors in elderly patients with recent-onset asthma should include a careful review of medications including self-prescribed ASA and other drugs with asthma-inducing potential (level II).

• Special care should be taken to allow elderly patients with asthma to choose an inhaler device with which they are comfortable and competent (level III).

• Measures should be taken to prevent osteoporosis in elderly patients with asthma who require prolonged treatment with oral corticosteroid (level I).

• Elderly patients with asthma require careful follow-up because they have an increased risk of exacerbations, which may be related to impaired perception of their disease severity (level II).