This could be due to sweat dermatitis or even jock itch - due to tinea infection. Keep the skin clean and dry,
avoid clothing that rubs and irritates the area. Application of topical over-the-counter antifungal or drying
powders, such as those that contain miconazole, clotrimazole, or tolnaftate would help. If symptoms persist -
it would be best that to consult a doctor. Regards.