Becky McCall

December 13, 2010

December 13, 2010 (Dubai, United Arab Emirates) — Despite being a highly treatable disease, asthma is poorly managed in older people because of frequent confusion with chronic obstructive pulmonary disease (COPD).

The scale of the problem is growing as the prevalence of both diseases rises in this population, pulmonologists reported here at the World Allergy Organization 2010 International Scientific Conference.

Stephen Holgate, MD, DSC, FRCP, professor in respiratory and immunopharmacology medicine from the University of Southampton Medical School and Southampton University Hospital Trust, United Kingdom, discussed the issues during his presentation.

"This is a confusing area and many diseases are mistaken for asthma in elderly patients. The 2 diseases may also occur together, but the asthmatic component is rarely treated adequately. Overall, this leads to needless suffering at a time when the numbers of such patients are increasing," he told Medscape Medical News.

During his presentation, Dr. Holgate described the characteristics of asthma that help differentiate it from COPD. Airway hyperresponsiveness, which leads to recurrent episodes of wheezing, dyspnea, chest tightness, and coughing, is common in asthma. Asthma symptoms usually respond to corticosteroid treatment, whereas COPD symptoms typically do not.

"Historically, this is a diagnostic way of separating the 2 diseases. The problem in older people is that there is an overlap of syndromes, both of which give rise to airflow obstruction. The biology of this hybrid group is poorly understood," Dr. Holgate said.

Treatment trials do not necessarily help. He explained that the criteria used to separate the 2 diseases are relative rather than absolute. Some COPD patients respond to bronchodilators or corticosteroids, whereas some asthma patients lose their bronchodilator response and their steroid response.

"Even high-resolution [computed tomography] scans don't necessarily distinguish the difference. We really do need much better diagnostic tests to disaggregate these complex disorders," Dr. Holgate said.

Symptomatically, there are some guidelines, particularly in the primary care setting, that can be used to distinguish between the 2 diseases, he said.

Using the patient's history of asthma allows for slightly more precision. "Onset in early life, symptoms that are more variable (although not necessarily), a tendency toward a diurnal pattern for asthma (although not necessarily), and often allergies and comorbidities such as atopic dermatitis are found in asthma but not COPD."

Dr. Holgate pointed out that it can still be confusing because patients with asthma can have a family history, but patients with COPD can, too.

Dr. Holgate noted that the onset of symptoms in middle life, a slow progression, a history of smoking, shortness of breath that increases with exercise in a progressive nature, and irreversible airflow obstruction all suggest COPD rather than asthma.

"Reversible airway obstruction is a symptom that can sometimes be lost in patients with chronic severe asthma."

A trial treatment with corticosteroids is considered the ultimate test to distinguish asthma from COPD. However, this is not fail-safe. Dr. Holgate pointed out that asthmatics who smoke, those with severe asthma, and those with concomitant COPD have symptoms that are all refractory to corticosteroids because of an alteration in the histone deacetylase enzyme, which provides steroid responsiveness.

Furthermore, he pointed out that patients with chronic obstructive or "fixed" asthma show a decline in lung function over time, which is more severe and rapid in patients with nonallergic asthma, often seen later in life. "This type of asthma does not necessarily respond to corticosteroid therapy," he said.

Also, in the older population, patterns of mortality and morbidity from asthma are different than those seen in their younger counterparts. Dr. Holgate cited a study from Spain that compared the 2 groups. In the older group (>65 years), asthma severity progressively increased in 10% of those with mild disease, in 35% of those with moderate disease, and in 55% of those with severe disease. In contrast, disease progressed in 47%, 35%, and 18%, respectively, in younger patients.

Dr. Holgate added that asthma in older patients is associated with premature mortality — not from asthma itself, but from comorbidities such as diabetes or hypertension. "In contrast, patients with COPD die as a direct result of their disease, usually an infectious exacerbation or heart failure secondary to COPD-induced pulmonary hypertension."

Although Dr. Holgate's talk focused on the overlap between asthma and COPD, there are other syndromes that emerge in the over-65 population that confuse diagnosis further, such as "eosinophilic bronchitis syndrome with chronic cough but without airway hyperresponsiveness, bronchopulmonary aspergillosis, occupational asthma (which often results in misdiagnosis of asthma and COPD), Churg–Stauss syndrome, bronchial neoplasms (often diagnosed as asthma or COPD), endobronchial sarcoid (causes airway obstruction), bronchiectasis, and bronchiolitis obliterans," he concluded.

Commenting on the confusion between COPD and asthma in older people, Peter Calverley, MD, from the School of Clinical Science, University Hospital Aintree, in Liverpool, United Kingdom, agreed that distinguishing asthma and COPD is a real challenge in older patients with persistent symptoms.

"Functionally, the 2 conditions do become more alike as chronic asthma progresses to fixed airflow obstruction," Dr. Calverley said. "The key is to manage patients holistically and assess and treat the individual components of their clinical problems."

He said that patients often receive either too much of an unnecessary drug or too little of a beneficial one because of misdiagnosis or incorrect treatment. "Excessive attachment to inappropriate labeling can lead to some patients being given excessive doses of oral corticosteroids, while others are denied the benefits of anticholinergic drugs or pulmonary rehabilitation because the 'wrong' set of guidelines are being followed," he noted.

Dame Helena Shovelton, DBE, MBA, chief executive officer of the British Lung Foundation, agreed that it is an issue that needs highlighting. "Prof. Holgate is right to draw this difficult issue out. As more than 2.7 million people are thought to be undiagnosed with COPD in the United Kingdom, it is vital that the proper tests are conducted to ensure an accurate diagnosis when they are found. What nobody knows is how many people are diagnosed with asthma or COPD correctly, as there is this difficulty of diagnosis and considerable overlap in the disease registers," she told Medscape Medical News.

Dr. Holgate, Dr. Calverley, and Dame Shovelton have disclosed no relevant financial relationships.

World Allergy Organization (WAO) 2010 International Scientific Conference. Presented December 6, 2010.

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