Nystatin and triamcinolone cream treats fungal skin infections caused by yeast (candidiasis), a common cause of diaper rash, and vaginal and anal skin infections. It is a combination of two medicines; nystatin that treats fungal skin infections and triamcinolone, an anti-inflammatory corticosteroid (steroid), that relieves swelling, itching, and redness. It comes in a cream and an ointment and is applied to the skin, usually twice a day (in the morning and evening) or as indicated on your prescription. Do not use more than what is necessary to cover the infected area, and do not apply it more often then indicated by your doctor. It should not be used for more than 25 days. Wash your hands before applying the cream or ointment. Squeeze an amount necessary to distribute a thin layer on the infected area and rub it in. If possible, leave it open to the air without covering it with a bandage. Wash your hands again to avoid getting it in your eyes or mouth. If applying for diaper rash, leave the diaper loose.