Kenacort New 0.1% Mouth Ulcers Paste contains triamcinolone, a corticosteroid used to reduce inflammation in mouth ulcers. If used for a long period, it may cause mild side effects such as burning, itching, irritation, redness or dryness in the mouth or throat. In some cases, prolonged use may increase the risk of fungal infection in the mouth. If you notice any changes or symptoms in your mouth with long-term use, please consult your doctor.