It is usually apparent in early childhood and even in the first few days of life. About 50% of persons affected will develop the symptoms by 20 years of age.
Adults generally complain of pain, joint stiffness, and progressive deformity. In children the condition affects mainly the bones of the extremities and pelvis, and may result in limb length inequality, deformity, or joint contractures. Joint contractures may be accompanied by extraosseous bone formation.
The classic radiographic appearance is that of sclerotic lesions of bones that look like wax dripping down the side of a candle.
The clinical course is slowly progressive. Severe symptoms may require treatment by sympathectomy or even amputation.