Rare in the US, it’s mostly found in Turkey, and heading east on the Silk Road through Iraq, Iran, Arabia, to China, Korea, & Japan. It causes ulcers in the mouth and genitals. There’s often an arthritis of medium & large joints like knees, ankles and/or wrists. Any organ can be affected, like the eye, lungs, and more. Blood clots occur in veins; the brain is affected in severe cases. Rheumatologists have various treatments, both to calm symptoms and prevent damage.