What causes white patches on a child's face?

White patches appearing on a child's face may be caused by several different factors: 1. Post-inflammatory hypopigmentation: Melanocytes in the skin are produced in the basal layer of the epidermis and then transferred to each keratinocyte. When melanocytes are damaged, not only is the number of melanocytes in the basal layer reduced, but the melanin within the melanocytes may also decrease, leading to localized skin hypopigmentation. This condition may gradually repair itself over time. 2. Vitiligo: White patches on the face are one of the clinical manifestations of vitiligo. If left untreated, vitiligo may cause psychological distress or self-esteem issues in children. 3. Pityriasis alba: This is a skin disorder characterized by round or oval patches of light white coloration of varying sizes, accompanied by fine, scaly skin. 4. Congenital hypopigmented nevi (white birthmarks): These may appear at birth or shortly after, and may include Mongolian spots or nevus anemicus. These usually do not require treatment. 5. Fungal infections: Such as pityriasis versicolor, which is caused by fungal infection and may lead to hypopigmented patches on the face. 6. Other skin diseases: Conditions such as psoriasis and discoid lupus erythematosus may also result in abnormal skin patches.