Thanx for you query.
Whenever arthritis is there generally the swelling is accompanied by pain during movements of joint along with redness
and tenderness .You have not mentioned your age because that is useful to determine type of arthritis if any existing . It could be due to sprain as the history you are giving is of short duration just 4 days but we cant be sure for this unless you are investigated. osteoarthritis
generally does not lead to swelling on base of fingers . You should consult a rheumatologist
, get your inflammatory markers
like ESR,CRP, routine tests and other specialised tests if required to rule out arthritis . If they all turn out to be negative see an orthopaedician for any injury related stiffness
and swelling of finger.You are advised to consult a doctor early for your problem.
Wishing you good health.