Hi based on ur history it could be pityriasis alba an eczematous condition which is very common , it can be self resolving , apply moisturisers more frequently and if it doesn’t come down anti inflammatory agents are needed
There are many skin care lotions for children ur dermatologist shall examine and give best suitable brands for kids skin type
Next Steps
Use moisturiser
Consult qualified dermatologist if it’s not reducing or if it’s increasing
Health Tips
Avoid very hot or cold water bath
Apply moisturisers immediately after bath