Acute cough in the elderly: aetiology, diagnosis and therapy

Although the frequency of physician consultations and the sale of over-the-counter remedies establish the high prevalence of acute cough in the elderly, epidemiological studies have tended to be imprecise. However, respiratory tract infections in nose, larynx and/or bronchi, either viral or bacterial or both, are by far the commonest cause of acute cough. These are especially frequent and hazardous in the elderly, and community living and institutionalisation may aggravate this problem. A variety of viruses and bacteria have been incriminated, with rhinovirus, influenza and respiratory syncytial viruses, and Streptococcus pneumoniae, Haemophilus influenza and Bordetella pertussis being especially important. Viral infections can readily lead to community-acquired pneumonia. Successful diagnosis should point to successful treatment, and in this respect clinical examination and patient history are paramount, supplemented by chest X-ray, viral and bacterial culture and serological testing. Depending on the results of these tests, specific antibacterial therapy may be called for, although there is dispute as to the merits of antibacterial therapy in cases of uncertain diagnosis. Prevention and prophylaxis for influenza and S. pneumoniae infections are now commendably routine in the elderly, especially those in communities. Treatment, as well as the use of antibacterials, may also be directed against the inflammatory and infective processes in the airways. Non-specific antitussive therapy is common and usually highly desirable to prevent the adverse effects of repeated coughing. There have been few advances in antitussive therapy in recent years, opioids and dextromethorphan being the most commonly used agents; they act centrally on the brainstem, but also have a large placebo effect. However they work, they are much appreciated by patients and their partners. Moreover, striking advances in our understanding of the peripheral sensory and central nervous pathways of the cough reflex in recent years should soon lead to a new and more specific choice of agents to inhibit cough.