If you have not applied any cream already, With your history and the picture, it looks like a fungal infection(tinea corporis). Or it can be due to increased sweat retention, allergy, contact dermatitis.
Next Steps
consult me online/ chat so that I ask further questions, photos and come into proper diagnosis and give a proper prescription.
Health Tips
DON'T APPLY any cream/ointment/anything by yourself or from medical store guy. though they might decrease initially as they have steroids, it'll be cause spreading of the problem to other area and cause skin damage.