Hello
Thanks for posting your query at DoctorSpring.com
I understand your concern.
This seems to be like a fungal infection in the pic. It's called tinea. There also seems to be some kind of allergic component.
I would recommend that you apply clotrimazole cream and cortisone cream twice a day for a week and see if it helps.
In case it doesn't subside, then it would be best to visit your doctor.
Please let me know if you have any queries.
Take care
Regards