When antibiotics are unnecessary.

Dermatologists can decrease unnecessary use of antimicrobial agents by avoiding them in situations wherein good evidence indicates that they are ineffective. Controlled trials indicate that antimicrobial agents are unhelpful in treating cutaneous abscesses, inflamed epidermal cysts, uninfected atopic eczema, and cutaneous ulcers caused by venous insufficiency or diabetes in the absence of significant contiguous soft-tissue inflammation. Prophylactic antibiotics are rarely appropriate for routine dermatologic surgery and are not indicated for patients who have prosthetic joints or vascular grafts. They are recommended only for a small group of patients who have abnormal cardiac valves, and then only with surgery involving clearly infected skin or soft-tissue. Topical antibiotics are no better than white petrolatum in covering sutured wounds, and with moist occlusive dressings, no ointment is necessary.