I just took my two year old in last week for the same thing. She has many white spots and the doctor said they are more prevalent in summer when they tan. Even though most of the spots were smooth, he said it was a form of eczema. I think he saw 2 spots that were actually rough. He said to lotion her up every morning, night, and after baths. Oatmeal baths were good. Also gave me a prescription if she was itching and said taking zyrtec would help her since its caused by allergies. The information sheet he gave me said it is common in areas that crease (like inside crease of arm, behind knees, kneck, etc.), which fits my daughter. She gets whiter behind the knees and in other creases. My daughter doesn't itch though but I am still putting tons of lotion on.