A raised, reddened, intensely itchy lesion in the areas of skin to skin contact in the groin is characteristic of Tinea Cruris, which is also known as "Jock Itch." It is caused by a fungal infection.

The diagnosis can be made on the basis of the typical appearance of the lesion, but can be confirmed by scraping the margin of the lesion and suspending the scrapings in KOH. A microscopic exam will reveal the typical threads of fungus.

Treatment is any conventional anti-fungal agent. If topical treatments are used, it may take up to several weeks to achieve a cure, even when applied two or three times a day. The fungus resides beneath the keratinized layer of skin and it takes time and persistence for the anti-fungal agent to penetrate through the skin to get at the fungus.

Prevention involves avoiding the predisposing factors of heat and moisture.