Hello, I can understand your concern for thigh boil with reducing swelling and scabbing. You have not told us your age, sex and related medical history so that I should have helped you better. In case If you are not diabetic or do not have any other systemic illness then you don’t have to be worried for anything. I can get from your history that boil is reducing and there is scab formation so it shows a good sign of healing. I suggest you to check your sugar level if you are more than 35 years of age. It is one of the sole most important factors in reducing the tendency of the boils. Do not scratch or rub the skin as it can lead to further aggravation. In my patients I suggest them ot apply a cream containing antibiotic such as mupirocin or gentamycin to be applied over the affected area. If at all you feel that the area is increasing or there is more of aggravation of the problem then you can meet a family physician immediately. All the best.