Fungal infection in the groin area under tight clothing is usually caused by heat, sweating and moisture trapped in skin folds. You may apply a topical antifungal cream, such as clotrimazole or terbinafine, to the affected area twice daily after thoroughly washing and drying the area. Continue using it regularly for 2 to 4 weeks, even if symptoms improve early, to prevent recurrence. Avoid using creams that contain steroids, as they can worsen fungal infections or delay healing. Do not share towels or clothing. Wash underwear daily and keep the area as dry as possible throughout the day. Wear loose cotton underwear and avoid tight clothing that causes rubbing or sweating. After physical activity or sweating, gently clean and dry the area. Try not to scratch the affected skin, as it can lead to further irritation. If there is no improvement after 2 weeks or the infection keeps recurring, please consult a doctor for further evaluation, as you may need oral antifungal treatment such as terbinafine or itraconazole.