Elderly patients should be considered immunocompromised for several reasons: 1. T cell function and reduced cellular immunity occur as we get older. 2. B cell antibody production decreases. 3. Host defenses against infection are reduced with aging, such as reduced circulation and thinning skin. 4. Miscellaneous factors, such as malnutrition and co-existing illnesses contribute to increased risk of infection as well.
[Good reference and suggested reading: Hals G. Common diagnoses become difficult diagnoses when geriatric patients visit the emergency department: Part I. Emergency Medicine Reports 2010;31(9):103-111.]
