Thank you for your query.
A photograph would have helped.
Apply a aloe vera
lotion to the area thrice daily for 10 days.
Give him zinc suspension for 14 days.
Deworm the child.
Consult your doctor if the problem persists.
If you have any further queries you are free to consult me.
Hope this answers your query.
Wishing a speedy recovery.
Have a nice day.