Lot of children get this and its noticed at the end of summer, one cause could be called Pityriasis alba means (,white scaly
patches) very common after summer
skin exposure ,cheeks, face upper trunk ,upper arms .the
patches are dry with very fine scales ..put daily moisturiser on , Aquaphor is good .Other cause is a fungal infection called tinea versicolor, this is most common in young adolescents.may need some treatment ask the Doctor about this one ..nothing to worry about ..