Hello, Your daughter has a sore area on the inner thigh. There is also a rash developed on the affected area. The rash occurs commonly due to jock itch, she can apply Clotrimazole ointment on the affected area. Taking a short course of anti fungal orally is effective. Chaffing can cause discomfort, she should wear soft cotton clothes and take care of her hygiene. Take bath regularly. It can also be due to dermatitis( atopic/contact). For precaution, she should not share her toiletries or clothes with anyone. If sexually active then STD tests should be done to rule out any sexually transmitted diseases like herpes, sec. syphilis, etc. She can take non sedating antihistamines, to prevent itching and other allergic symptoms. Cold compress is helpful. To reduce soreness, she should take plenty of water to hydrate the muscles and flush out toxins. Simple hydration can help her recover at a faster pace. She can take analgesics, one stat when needed to reduce pain, inflammation and soreness. She should give rest to her legs, avoid walking or exerting. She can do light stretching exercises as the soreness starts to reduce. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician