In medical term it is called pityriasis versicolor and it is caused by fungi...so inorder to treat it first always u have to keep ur body and cloth clean and if it appears around ur neck stop using a necklaces until its gone. The first treatment if it appears in small place in small amount 1, ketoconazole shampoo (brand name vavo) 2, ketoconazole tablets one each everyday after food (but the tablet is only recommended if u don't have heart, liver and kidney disorder) Second if it appears in large amount of ur body part 1, candacort cream (use it in the morning at night and apply it after u wash ur body and change ur close everyday) 2, Terbinafine (terbonile brand)tablets take one every night for morethan 20 days Am not a doctor but am a health student