Redness, itching, pain in sweaty areas.

I am a 42-year-old woman. My problem started in June 2025. Initially, I developed redness and severe itching in the inner thigh (groin) area. There were no bumps or rashes, just redness and irritation. I consulted a doctor and was prescribed antifungal medication (itraconazole), anti-allergic medicine, and a dusting powder, which relieved the symptoms.However, after about three months, the problem returned. Later, it also started appearing under the breasts and in the underarm areas. I consulted another doctor and received similar treatment, which again improved the condition temporarily.Now, the issue keeps recurring more frequently. The itching has reduced, but I am noticing red to dark (blackish) patches in the affected areas. Sometimes, the area becomes sticky, painful, and irritated instead of itchy. It improves with medication but comes back again, and now I need to apply creams regularly to control it. All the blood works were normal at that time . Plz tell me what is this