Hello
Thanks for posting your query at DoctorSpring.com
I can understand your concern. I reviewed the picture.
It seems to be fungal infection called tinea. There seems to be an associated allergy as well.
I would recommend application of lamisil cream twice a day for two weeks . You could apply cortisone cream after two week , for 5 days once a day (if rash still persists)
This should help resolve the infection.
Please let me know if you have any queries.
Take care