Hi, An itchy rash in the buttocks and vaginal area after taking an antibiotic could be a sign of a yeast infection or a bacterial infection. Here are some steps you can take to treat the rash: * Keep the area clean and dry: Use gentle soap and lukewarm water to clean the affected area, and then pat dry with a clean towel. Avoid rubbing the area vigorously. * Apply a topical cream: Over-the-counter antifungal or antibacterial creams, such as clotrimazole or Neosporin, may help to reduce itching and inflammation. Apply the cream to the affected area according to the instructions on the packaging. * Wear loose-fitting clothing: Tight-fitting clothes can trap moisture and aggravate the rash. Wear loose-fitting clothing made of breathable fabric like cotton. * Avoid scratching: Scratching can make the rash worse and increase the risk of infection. Try using a cool compress or taking an oatmeal bath to soothe the itching. * See a doctor: If the rash does not improve or gets worse after a few days of home treatment, it is best to see a doctor. They can diagnose the cause of the rash and prescribe appropriate treatment, such as prescription antifungal or antibiotic medication. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Priyanka, General & Family Physician