Hello,
It seems to be having cellulitis turning to abscess as a result of that injection (which could be septic). Your mild fever could be the reason of this septic abscess.
You can feel the swelling by the back of your hand and it will be warm to touch that also suggests some sort of infection.
You can take ibuprofen with the
antipyretic combination ( tab.combiflam available over the counter) with antacid (
pantoprazole 40 mg).
But as I said earlier this kind of large abscess needs
incision and drainage (I&D) under
local anesthesia for which you should see a surgeon.
And it is a daycare procedure which will be followed by
oral antibiotics, anti-inflammatory, and analgesics with other supportive treatment.
Here,do not start an antibiotic without consulting surgeon as it may lead to antibioma formation.
Hope I have answered your query. Let me know if I can assist you further.
Take care
Regards,
Dr Ivan R. Rommstein, General Surgeon