Sudden onset acute polyarticular arthritis. mild thrombocytopenia. substantial swelling at knees, but also small joints hands feet. mild fever, malaise, no skin invlmt. happens every 10 yrs > hospital?

Outpatient.: If this is recurrent we already have some insight into what it is or at least what it has not been in the past. Don't see any reason for the hospital but sounds like you would benefit from rheumatology involvement and perhaps some routine lab studies.

See your doctor now: Hard to say without further workup.Your symptoms are perhaps most worrisome for flares of latent viral infection that is activated with stress. Gonorrhea usually is associated with a rash but can cause a severe polyarticular arthritis. Not usual for lyme dis. If you had a chronic autoimmune disease like psoriatic arthritis flares would be more frequent unless you are on arthritis controller meds.