Canesten Antifungal Cream Canesten Antifungal Cream treats fungal skin infections such as ringworm, athlete's foot, fungal nappy rash & fungal sweat rash. It is also be used to relieve irritation of the vulva (external thrush) or the end of the penis, which may be associated with thrush. The active ingredient in Canesten Antifungal Cream is clotrimazole, an antifungal agent that fights the cause of fungal skin infections.