No one is sure what causes Munchausen syndrome by proxy. Sometimes, the person was abused as a child or has Munchausen syndrome (fake illness for themselves).

The caretaker can do extreme things to fake symptoms of illness in the child. For example, the caretaker may:

• Add blood to the child's urine or stool
• Withhold food so the child looks like they can't gain weight
• Heat up thermometers so it looks like the child has a fever
• Make up lab results
• Give the child drugs to make the child throw up or have diarrhea
• Infect an intravenous (IV) line to make the child sick

What are the signs in a caretaker?

• Most people with this problem are mothers with small children. Some are adult children taking care of an older parent.
• The caretakers often work in health care and know a lot about medical care. They can describe the child's symptoms in great medical detail. They like to be very involved with the health care team and are liked by the staff for the care they give the child.
• These caretakers are very involved with their children. They seem devoted to the child. This makes it hard for health professionals to see a diagnosis of Munchausen syndrome by proxy.

What are the signs in a child?

• The child sees a lot of health care providers and has been in the hospital a lot.
• The child often has had many tests, surgeries, or other procedures.
• The child has strange symptoms that don't fit with any disease. The symptoms do not match the test results.
• The child's symptoms are reported by the caretaker. They are never seen by health care professionals. The symptoms are gone in the hospital, but start again when the child goes home.
• Blood samples do not match the child's blood type.
• Drugs or chemicals are found in the child's urine, blood, or stool.

To diagnose Munchausen syndrome by proxy, providers have to see the clues. They have to review the child's medical record to see what has happened with the child over time. Very often, Munchausen syndrome by proxy goes undiagnosed.

The child needs to be protected. They may need to be removed from the direct care of the caretaker in question.

Children may require medical care to treat complications from injuries, infections, medicines, surgeries, or tests. They also need psychiatric care to deal with depression, anxiety, and post-traumatic stress disorder that can happen with child abuse.

Treatment most often involves individual and family therapy. Because this is a form of child abuse, the syndrome must be reported to the authorities.

If you think a child is being abused, contact a provider, the police, or child protective services.

Call 911 or the local emergency number for any child in immediate danger because of abuse or neglect.

You can also call this national hotline. Crisis counselors are available 24/7. Interpreters are available to help in 170 languages. The counselor on the phone can help you figure out the next steps. All calls are anonymous and confidential. Call Childhelp National Child Abuse Hotline 1-800-4-A-CHILD (1-800-422-4453).

Recognition of Munchausen syndrome by proxy in the child-parent relationship can prevent continued abuse and unnecessary, expensive, and possibly dangerous medical testing.

Factitious disorder by proxy; Child abuse - Munchausen

Byrne R, Elsner G, Beattie A. In: Kliegman RM, Toth H, Bordini BJ, Basel D, eds. Nelson Pediatric Symptom-Based Diagnosis. 2nd ed. Philadelphia, PA: Elsevier; 2023:chap 31.

Carrasco MM, Wolford JE, Eichman AL. Child abuse and neglect. In: Zitelli BJ, McIntire SC, Nowalk AJ, Garrison J, eds. Zitelli and Davis' Atlas of Pediatric Physical Diagnosis. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 6.

Dubowitz H, Lane WG. Abused and neglected children. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 16.

Young HW, Thornton JE. Factitious disorders and malingering. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 100.

Updated by: Neil K. Kaneshiro, MD, MHA, Clinical Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.