It is comparatively easy to diagnose this disease as the signs are visual and cover specific regions of the body (the area in front of and behind the knee. Anyway, it is important to see the health care provider to detect the problem accurately as well as learn about the causes mentioned above. The initial procedure to pass is a special physical test aimed to define the nature of the lumps and nodules. Health care providers should pay attention to the distribution and progress of skin lesions, their color, shape, and the condition of joints.