Prescription anti-inflamatories (Vioxx, etc.) may not be necessary- they are for pain control. Ibuprofin, aspirin, etc., non-prescription, may be fine for you, as mentioned in a post above. Ask your doctor.

Heat plus exercise seems to be a sine qua non.

There are a thousand and one hearsay remedies, some harmless, some potentially dangerous. Recent laboratory tests on HENNA indicate that it is a potential carcinogen. It is a fashion thing with East Indian women, decorating their hands.
Coal tar is the most ancient treatment, and even the Mayo Clinic mentions it- how it works, no one knows, but it seems to help many minor cases. They say it seems to have few side effects. Also use moisturizers (sp.?).
Read the Mayo Clinic article and then talk to your doctor. Ask him if your psoriatic condition is D. I. P. (no, I won't try to spell it) which is very common. Affects terminal joints of fingers and toes. See Mayo article.
By the way, I can find no reliable recommendation of vinegar- which suits me, because of my allergy to it.
A new treatment seems to be ultraviolet therapy.