自傷行為に関する新たな知見

A newly emerging, distinct form of self-mutilation among adolescents was described for the first time by a team of radiologists at the annual meeting of the Radiological Society of North America (RSNA). This condition, termed self-embedding disorder, involves insertion of foreign bodies into soft tissues.

"Radiologists are in a unique position to be the first to detect self-embedding disorder, make the appropriate diagnosis and mobilize the healthcare system for early and effective intervention and treatment," said the study's principal investigator, William E. Shiels II, D.O., chief of the Department of Radiology at Nationwide Children's Hospital in Columbus, Ohio.

Self-injury, or self-harm, refers to a variety of behaviors in which a person intentionally inflicts harm to his or her body without suicidal intent. It is a disturbing trend among U.S. adolescents, particularly girls. Prevalence is unknown because many cases go unreported, but recent studies have reported that 13 to 24 percent of high school students in the U.S. and Canada have practiced deliberate self-injury at least once. More common forms of self-injury include cutting of the skin, burning, bruising, hair pulling, breaking bones or swallowing toxic substances. In cases of self-embedding disorder, objects are used to puncture the skin or are embedded into the wound after cutting.

The behavior had a number of other unique characteristics, Dr. Shiels said, the most troubling of which was a close relationship with suicidal ideation or behaviors. For example, he said, "one girl wrote 'kill me' in blood on her arm and then embedded a foreign object in her bicep."

Ninety percent of cases voiced suicidal ideation and 70% have repeated the behaviors with increasing larger and more objects. Post-traumatic stress disorder following significant chronic abuse (physical and sexual abuse) was a common feature in these teens. The 10 children included in the study shared histories of physical or sexual abuse and all were in either group homes or foster care.

Dr. Shiels and colleagues studied 19 episodes of self-embedding injury in 10 adolescent girls, age 15 to 18. Using ultrasound and/or fluoroscopic guidance, interventional pediatric radiologists removed 52 embedded foreign objects from nine of the patients. The embedded objects included metal needles, metal staples, metal paperclips, glass, wood, plastic, graphite (pencil lead), crayon and stone. The objects were embedded during injuries to the arms, ankles, feet, hands and neck. One patient had self-embedded 11 objects, including an unfolded metal paperclip more than six inches in length.

Ultrasound guidance allowed the researchers to detect the presence and location of wood, crayons and plastic objects, not detectable on x-ray examinations. Removal was performed through small incisions in the skin that left little or no scarring and was successful in all cases, without fragmentation or complications.

"This technique offers surgeons and emergency physicians a safe and effective alternative for removal of foreign bodies, including objects at risk for fragmentation during traditional operative techniques," said co-author Adam Young, B.S. "The small incision minimizes scarring and deformity, which is key for the self-esteem of this unique, high-risk group of patients."

The patient profile "suggests this is a discrete entity," Dr. Shiels said. "We couldn't find it anywhere in the literature. We have started a web-based, secure registry for physicians to submit their own cases."

Co-authors are James Murakami, M.D., Brian Coley, M.D., and Mark Hogan, M.D.