Patients with CTO often present in early childhood, typically at 2 to 3 years of age with joint pain, joint swelling, and decreased mobility at the wrists or ankles.3,4 Pain commonly decreases with disease progression. Joint involvement is usually bilateral, although, at initial presentation, it may be asymmetric. With progressive bone resorption, the natural course of the disease leads to joint deformity with hypermobility and subluxation, and eventually to significant musculoskeletal impairment. The results of laboratory investigations are typically normal, including inflammatory markers. Occasionally, facial dysmorphism has been described, including micrognathia, hypertelorism, triangular face, frontal bossing, and other skull deformities.3,5 Radiographic studies typically confirm the diagnosis and can help distinguish the disease from other arthropathies such as juvenile idiopathic arthritis. Plain radiographs reveal progressive osteolysis of the carpal and tarsal bones, as well as adjacent tubular bones (eg, metacarpal bones and phalanges). Resorption of other bones, including elbow involvement, although uncommon, has been reported. At presentation, radiographs may be normal, making it difficult to establish a diagnosis unless radiography is performed again months or even years later. In general, the overall health and well-being of the individual are not typically affected, and the disease process often stabilizes between the ages of 20 and 30 years for most individuals.