What should an older adult do about a diaper rash?

Irritation vs yeast: The two most likely causes are irritation or yeast infection. A soothing cream or ointment will usually help with irritation. An anti-fungal cream (clotrimazole, miconazole, terbinafine, and others) can help with yeast. There are powders that can help also, like zeasorb af which contains an anti-fungal component.

Adult diaper rash: For adult “diaper” rash keep skin clean & dry. Change diaper as soon as it's soiled or wet. For healing go without diaper for periods of time so affected area can air out. Avoid tight diapers or airtight covers over diaper. Meds your Dr. might recommend include antifungal cream (for fungus), a steroid cream (for significant inflammation) or an antibiotic (for bacterial infection.)