Hi I am Dr Fahim, General Surgeon and I will looking into your problem . . . Its sad to know that you are suffering from this condition. But encouraging thing is that it is fully curable and you will be fine in few days time if you follow my advice. You are had an abscess in the arm, which is now ruptured with pus draining out so the pain as well as size will reduce. That pus needs to be sent for culture sensitivity, to know about the organisms involved and appropriate antibiotics to which it will respond. If such patient walk in my clinic, I plan for local treatment of the wound under local anaesthesia. All the pus is drained and any dead tissue removed, so that focus of infection is eliminated. This process is repeated on daily basis for approximately 5 days. Second empirical systemic antibiotic cover eg (amoxillin&clavulanate) is started till the culture sensitivity report is not available. Analgesic eg Paracetamol is needed for pain control. You need to see a general surgeon to accomplish all these tasks and it is not going to heal on its own. I hope it will help you with your problem. Do rate my answer if you like it. Regards