Hello, I think you have neglected your health a little and have become overweight which might be the cause for your knee pain and simultaneous rashes may be coincidental which is caused due to an allergy or infection which can be treated with any antihistaminics or antibiotics for five days. But you need to take care of your weight. You have to diet to control it. Eat good food with most nutritious like fruits, vegetables, etcetera. Don t eat junk foods at all. Avoid rice and sugar based products. Eat wheat-based products more. Oats, cornflakes can be eaten. Take six to eight frequent meals to avoid hyperglycemia. Get your sugars tested and rule out diabetes. Exercise regularly Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Archana