Two days ago, after I had had my bath, I noticed those white spots on my arm below on my right leg; they were about six to seven of them scattered on it just like the picture below, I was puzzled at first but after I dried my body with a towel, it disappeared. It didn't happen yesterday after bath, but it did again this morning when I was rinsing my hands so I quickly took a picture of it to inquire. I tried to scratch it off but it never yield. They are no longer on my arms now as I typed this. Have anyone here experience this? What could be the cause of this?