Caffey disease

Synonyms

1

Overview

Caffey disease, also called infantile cortical hyperostosis, is a bone disorder that most often occurs in babies. Excessive new bone formation (hyperostosis) is characteristic of Caffey disease. The bone abnormalities mainly affect the jawbone, shoulder blades (scapulae), collarbones (clavicles), and the shafts (diaphyses) of long bones in the arms and legs. Affected bones may double or triple in width, which can be seen by x-ray imaging. In some cases two bones that are next to each other, such as two ribs or the pairs of long bones in the forearms (radius and ulna) or lower legs (tibia and fibula) become fused together. Babies with Caffey disease also have swelling of joints and of soft tissues such as muscles, with pain and redness in the affected areas. Affected infants can also be feverish and irritable.

The signs and symptoms of Caffey disease are usually apparent by the time an infant is 5 months old. In rare cases, skeletal abnormalities can be detected by ultrasound imaging during the last few weeks of development before birth. Lethal prenatal cortical hyperostosis, a more severe disorder that appears earlier in development and is often fatal before or shortly after birth, is sometimes called lethal prenatal Caffey disease; however, it is generally considered to be a separate disorder.

For unknown reasons, the swelling and pain associated with Caffey disease typically go away within a few months. Through a normal process called bone remodeling, which replaces old bone tissue with new bone, the excess bone is usually reabsorbed by the body and undetectable on x-ray images by the age of 2. However, if two adjacent bones have fused, they may remain that way, possibly resulting in complications. For example, fused rib bones can lead to curvature of the spine (scoliosis) or limit expansion of the chest, resulting in breathing problems.
Most people with Caffey disease have no further problems related to the disorder after early childhood. Occasionally, another episode of hyperostosis occurs years later. In addition, some adults who had Caffey disease in infancy have other abnormalities of the bones and connective tissues, which provide strength and flexibility to structures throughout the body. Affected adults may have loose joints (joint laxity), stretchy (hyperextensible) skin, or be prone to protrusion of organs through gaps in muscles (hernias).

 

Symptoms

Caffey disease is characterized by excessive new bone formation (hyperostosis). The bone abnormalities mainly affect the jawbone, shoulder blades, collarbones, and the shafts of long bones in the arms and legs. Affected bones may double or triple in width. In some cases, two bones in the forearms or lower legs become fused together. Babies with this condition may also develop swelling of joints and soft tissues with pain and redness in the affected areas. They may also be feverish and irritable.

The signs and symptoms of Caffey disease are usually apparent by the time an infant is 5 months old. In rare cases, skeletal abnormalities can be detected by ultrasound during the late stages of pregnancy. For unknown reasons, the swelling and pain associated with Caffey disease tend to go away within a few months. The excess bone also disappears as it is reabsorbed by the body through a normal process called bone remodeling. If two bones have been fused, they may remain that way, which can lead to complications such as scoliosis and breathing problems.

Most people with Caffey syndrome have no further problems related to the disorder after early childhood. Occasionally, another episode of hyperostosis occurs years later. In addition, some adults who had Caffey disease have other abnormalities of the bones and connective tissues, including loose joints, stretchy skin or hernias.

Causes

Caffey disease is caused by a mutation in the COL1A1 gene. It is inherited in an autosomal dominant pattern, but not all people who inherit the mutation develop signs and symptoms. This is due to incomplete penetrance.

The COL1A1 gene provides instructions for making part of a large molecule called type I collagen. Collagens are a family of proteins that strengthen and support many tissues in the body, including cartilage, bone, tendon, and skin. In these tissues, type I collagen is found in the spaces around cells. The collagen molecules are cross-linked in long, thin, fibrils that are very strong and flexible. Type I collagen is the most abundant form of collagen in the human body.

Diagnosis

Most infants with infantile cortical hyperostosis are diagnosed by physical examination. X-rays can confirm the presence of bone changes and soft tissue swelling. Biopsy of the affected areas can confirm the presence of typical histopathological changes. No specific blood tests exist, but tests such as erythrocyte sedimentation rate (ESR) and alkaline phosphatase levels are often elevated. A complete blood count may show anemia (low red blood cell count) and leukocytosis (high white blood cell count). Other tests may be done to help exclude other diagnoses. Ultrasound imaging can help diagnose prenatal cases.

Prognosis

Infantile cortical hyperostosis is a self-limited condition, meaning that the disease resolves on its own without treatment, usually within 6-9 months. Long-term deformities of the involved bones, including bony fusions and limb-length inequalities, are possible but rare.

Resources

• NIH
• Genetics Home Reference