Tinea cruris is also known as jock itch. It refers to the fungal infection of the moist areas especially groin and inner thighs. People who are obese, diabetics, immunodeficient, sweat a lot, and athletes usually get this type of fungal infection. In tinea cruris, skin is erythematous. Associated burning sensation and itching is common. Small blisters may also be present. The diagnosis of tinea cruris is clinical. Over-the-counter antifungals are indicated in form of lotion, ointment, or powder. The infection clears within 1-2 weeks. Reference: https://www.mayoclinic.org/diseases-conditions/jock-itch/diagnosis-treatment/drc-20353812
The best anti-fungal is clotrimasole lotion using twice daily but the best way to prevent its recurrence is to keep the site dry & wash it with baby shampoos& dry properly