Hi. I am using a whitening soap (kojic). The process is I am rubbing the soap to my body then I am waiting for at least five minutes for the soap to stay in my body. Because I thought that the longer the soap is staying at your body, it will make my skin Whitier. But unfortunately my armpit darken. And I think it was a burn. Because when I was bathing I felt a hot and burning feeling. Now my armpit is dark. And I am not confident to myself. How can I get rid of it? Somebody please answer..