This is a fungal infection. Wash the area well with antibacterial soap, dry well. Apply some Lamisil cream to the area. You will see an improvement in a couple of days, but do continue the cream for a week later to make sure the fungus is gone.
In the mean time wear loose fitting clothes so air can also get to the area.
Hope this helps, If you need anything else please feel free to ask. If you found this helpful don’t forget to click the *
Healthcare Expert
17+ years, Healthcare Expert