It sounds like you may have tinea cruris, a fungal infection affecting the inner thighs and buttocks. This condition typically requires 4 to 6 weeks of antifungal treatment, including both oral medication and topical creams. Meanwhile, you must take care of the following factors:

• Use antifungal medications as prescribed.
• Keep the affected area clean and dry.
• Avoid using soap on the area.
• Do not use steroid-containing combination creams as they can worsen the infection and lead to recurrence.
• Early treatment is key to preventing the infection from spreading to other parts of your body or to people in your household.