Caffy-Silverman syndrome (infantile cortical hyperostosis) [Abstract] Infantile cortical hyperostosis is a group of syndromes characterized by swelling, new bone formation and hypothermia in the full mandibular region of the bilateral face. Lu Xuemei, Department of Otolaryngology, Liaocheng People’s Hospital [Alias] Smyth syndrome; hffey disease. [Etiology] Familial onset is autosomal dominant, and there are a number of sporadic cases. [Pathogenesis] Due to malformation of periosteal vascular development or poor bone formation resulting in insufficient local blood supply and hypoxia, limited necrosis of soft tissue on the bone surface, resulting in periosteal hyperplasia and subperiosteal osteogenesis. [Pathology] In the early stage, the periosteum is swollen and mucinous with unclear borders, resembling osteosarcoma changes, and there may be infiltration of polymorphonuclear neutrophilic leukocytes, but there is no hemorrhage or inflammatory manifestations. In the later stage, the periosteum proliferates and new bone with poor vascular distribution and incomplete structure appears. [The familial type has a slightly earlier onset than the disseminated type, but generally occurs within the first 3 months of life. The child presents with low-grade fever, crying, and localized pain, and after a few days, swelling and hardening of the entire mandibular area on both sides, pale complexion, no redness or fever, no lymph node enlargement, and X-ray showing thickened bone cortex and new bone formation. In addition to the mandible, the tibia, ulna, ribs and fibula may be involved, and local pain and swelling may occur. [Diagnosis] Diagnosis can be made on the basis of clinical manifestations combined with X-ray examination, with attention to differentiation from mumps, which is characterized by bilateral swelling of the parotid area and abnormal redness and swelling of the parotid ducts. [Treatment] Symptomatic support. [Prognosis] Often resolves in a few weeks, with few recurrences, but a small number of children may die.