Radiographic overlap of recurrent Caffey disease and chronic recurrent multifocal osteomyelitis (CRMO) with considerations of molecular origins

Caffey disease, or infantile cortical hyperostosis, classically describes a self-limited inflammatory disorder that presents in the infant with fussiness, focal swelling and sometimes fever. Imaging is conventionally limited to radiography, which shows mild to profound subperiosteal bone formation and sometimes deformity. This disease was not uncommonly diagnosed in the late 20^th century. Interestingly, the disease may not just occur in the infant, and it may be due to a genetic mutation in the alpha-one chain of type 1 collagen (COL1A1). Recurrent or delayed onset in the older child or adolescent also occurs. In more recent years, another type of inflammatory bone disorder, chronic sterile osteomyelitis, has been frequently recognized and, depending on the radiographic stage or the diagnostic modality used, may have characteristics overlapping with Caffey disease. In this review, we discuss the demographics, imaging and known etiologies for Caffey disease and chronic recurrent multifocal osteomyelitis and raise the possibility of similar molecular origins.