Clinical features of pneumonia in the elderly.
Concomitant pneumonia and influenza constitute the leading infectious cause of death in the elderly and the fourth most common cause of death overall. The presence of concomitant illness and delays in diagnosis contribute to significant mortality from this disease in the elderly; senescence of the immune system seems less important in predisposition to pneumonia than the presence of concomitant illness. Delay in diagnosis is frequently secondary to the atypical presentations of pneumonia in the elderly. The usual symptoms of fever, chills, rigors, and sputum production that are present in young adults all may be absent; confusion may be the only presenting symptom. Tachypnea is frequent, but the physical examination, in addition to often being technically difficult, is not sufficiently sensitive in making a diagnosis. Leukocytosis is common, but by no means specific. Chest roentgenograms frequently show incomplete consolidation and findings are difficult to distinguish from other diseases of the elderly, such as congestive heart failure, atelectasis, pulmonary embolism, and malignancy. Therefore, clinical diagnosis requires a high index of suspicion despite atypical clinical manifestations.