This may be infected sebaceous cyst or simple foruncle.. or carbuncle ( common in diabetes , elderly or in steroid users) Check for sugars and if not in control..use appropriate medication for diabetes If it's cyst it should be removed along with it's Wall(outer layer) Then use appropriate antibiotics

Hello. Is he hairy? And the approximate size of the lump? If it's in hairy areas, it could be hair root infection ( furuncle) if it's small. If it's larger, it's probably a carbuncle - which is a bacterial infection. You can consult a dermatologist regarding this. If they rule out these , then can go to surgeon if needed.

Dear all, History itself is not yet clear Whether your patient is diabetic or not, if diabetic is it under the control or not, I like to know this one Most of the persons used to take regular & prolonged treatment for diabetes, but without any benefit For example, when a person needs 5 idly or 3 dosa for breakfast to alleviate the appetite, but the food provider gives only 2 idly or  1 dosa, is it possible to get rid of the appetite. Like that eventhough your patient is under regular treatment, I think he is under improper diabetic control. He may require further blood glucose control Try to achieve Euglycaemic level after proper periodic  consultation with a qualified diabetologist High blood sugar level-> Decreased immune power ( Immunosuppression) -> vulnerable for frequent infection, both fungal and bacterial -> recurrent Abscess formation ( Boils, carbuncle or infection of the existing sebaceous cyst) So, first treat the primary cause ( Consult a proper diabetologist) and equally  consult proper surgeon