Where does it come from?.. The poly-arthitritis is a condition caused by the mystery illness or a by product of it. Like systemic lupus which usually is diagnosed in young people and is more common among black folks. With this there could be flare ups of arthritic joints that come and go. Most people with this live mainly normal lives. The singer seal has lupus which is why his face is that way. Lupus is an autoimmune disorder in which the persons own immune system attacks joints, skin and even vital organs like the kidneys.