Dark spots appear on my kid’s skin No fever or any changes on his health?

Dark spots appear on my kid’s skin, they start from light to dark in hours until they flake. there are no itching, swelling, or bleeding. No fever or any changes on his health or daily activities. he had the same problem 3 months ago and continued for a week, a doctor said it’s fungi and will disappear without any intervention. after 3 months they start coming back on groups. if a spot shows up in right cheek, another one will shows up on the opposite side (left cheek). he lives in a dry environment and until now they show up in this winter.
please I need a second opinion.