thank you for query.with the description given it may be fungal infection.Please take following precautions.Use loose cotton clothes and inner wears.Keep area dry.Apply antifungals like clotrimazole.Once subsides use regularly antifungal dusting powders like candid or absorb powder to prevent recurrence in vaginal and groin area if present.Maintaining moisture free area is most important to prevent recurrence.Check if you have any diabetes.Treatment of both is important as infection keeps recurring.Avoid intercourse or Use condoms.consult doctor if does not subside.You can get back to me for any clarifications .Dr Bharatesh D Basti Dermatologist and Venereologist