This could be due to jock itch, tears or cuts due to friction, sweat dermatitis etc.
'Jock itch causes itching or a burning sensation in the groin area, thigh skin folds, or anus. It may involve the inner thighs and genital areas, as well as extending back to the perineum and perianal areas.'
Jock itch is treated with one of two types of antifungal medications — miconazole/ clotrimazole or terbinafine. Generally, terbinafine require a shorter treatment time, while azoles are less expensive but require longer treatment time.
For a mild case of jock itch, your doctor may suggest first using an over-the-counter antifungal ointment, lotion, powder or spray. Most infections respond well to topical agents.
You could read more about the condition at the following link -
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