Late onset asthma - Epidemiology, diagnosis and treatment

Asthma is common among older persons, affecting approximately 4 to 8% of th ose above the age of 65 years. Despite its prevalence, late onset asthma ma y be misdiagnosed and inadequately treated, with important negative consequ ences for the patient's health. The histopathology of late onset disease ap pears to be similar to that of asthma in general, with persistent airway in flammation a characteristic feature. It is less clear, however, that allerg ic exposure and sensitisation play the same role in the development of dise ase in adults as they do in children. Atopy is less common among those with late onset asthma, and the prevalence of elevated immunoglobulin E levels is lower among those aged over 55 years of age than younger patients. Occup ational asthma is an aetiological consideration unique to adult onset disea se, with important implications for treatment. The differential diagnosis for cough, wheeze, and dyspnoea in the elderly i s broad, and includes chronic obstructive bronchitis, bronchiectasis, conge stive heart failure, lung cancer with endobronchial lesion and vocal cord d ysfunction. Keys to accurate diagnosis include a good history and physical examination, the demonstration of reversible airways obstruction on pulmona ry function tests and a favorable response to treatment. Inhaled corticoste roid therapy is recommended for patients with persistent disease, and caref ul instruction in the use of metered-dose inhalers is particularly importan t for the elderly.