What Causes White Patch On Using Ayurvedic Cream For Acne?

Hi doctor, I had applied an ayurvedic cream for acne.....the acne was gone but now I can see white spot on my face where I had applied the lotion.....soon after that I consulted the doctor....the doctor had prescribed me to apply onabet B cream....but I find no result.....the white spot still remains as it is....they also told that it is not leucoderma....then y the cream is not helping it to go off my face