hi thank you asking your concern and welcome to HCM. there may be two possibilities for such kind of swelling after trauma and in abscence of any fracture. abscess or hematoma for both of the condition incision and drainage is the treatment. but first diagnosis has to be confirmed. i would suggest to meet any doctor he will first do aspiration with needle and see the fluid inside therehow diagnosis will be confirmed. next step will be incision. if swelling is large and pus is there then patient may need to shift on insulin for few days to have good healing or very few time it is not necessary. sugar control is must for healing. i hope i answered your concern and if you feel any doubt please ask us regards dr. Abhijit