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1.The possible cause of painful lump in an previously injured site - the possible cause infective collection.
2.In this case the it needs to be examined and an
ultrasound to assess any vascular involvement and blood supply and nature of lump, its extensions.
3.The treatment in this case will be a small
incision and drainage followed by a course of antibiotics and symptomatic treatment.
4.As a remedy do not squeeze or press, scratch the lump as it can further complicate, clean the area with antiseptic liquid.
5.Sugget to get in touch with your GP, get examined and treated accordingly. Good luck.
Hope i have answered your query,
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