You get vaccinated in the arm, you shouldn't have inflammation in the joint.
What happens is that the inflammation of the liver triggered by the infection causes it to contract and it becomes a fibrous blob.
Prednisone is often used to combat the inflammation brought on by autoimmune diseases.
"redness or swelling in a body part," early 15c., from Middle French inflammation and directly from Latin inflammationem (nominative inflammatio) "a setting on fire," noun of action from past participle stem of inflammare (see inflame). Literal sense in English from 1560s.
inflammation in·flam·ma·tion (ĭn'flə-mā'shən)
A localized protective reaction of tissue to irritation, injury, or infection, characterized by pain, redness, swelling, and sometimes loss of function.
The response of tissue to injury or infection. Pain, heat, redness, and swelling are the four basic symptoms of inflammation.