Thank you for your query.
This is post inflammatory exfoliation of skin probably a result of scarlet fever
ointment along with calamine and aloe vera
gel to the local area.Avoid tight pants and diapers.
Consult a dermatologist
if the lesions persists
If you have any further queries you are free to consult me.
Hope this answers your query.
Wishing your child a speedy recovery.
Have a nice day.