When Immunodeficiency Isn’t the Whole Story: CTLA-4 Haploinsufficiency and Munchausen by Proxy Syndrome

Introduction

Child abuse is defined as any behavior – intentional or unintentional – by an adult that negatively affects a child’s physical or psychosocial development (Violence Prevention Committee et al., Ann Emerg Med 2000; 36: 180). Among its various forms, Munchausen syndrome by proxy (MSBP) – formally classified as Factitious Disorder Imposed on Another (FDIA) in the DSM-5 – is a rare but severe form of abuse that is often difficult to diagnose and may lead to life-threatening outcomes.

The term “Munchausen” originates from Baron Karl Friedrich von Munchausen, an 18th-century figure known for telling exaggerated and fictitious stories about his adventures (Asher R et al., Lancet 1951; 1(6650): 339–341). The syndrome was first described by Roy Meadow in 1977 (Meadow R, Lancet 1977; 2(8033): 343–345).

MSBP is characterized by a caregiver – most commonly the mother – who fabricates or induces medical symptoms in a child. While the DSM-5 classifies this condition as FDIA, the term MSBP remains widely used in clinical pediatrics and child protection contexts (American Psychiatric Association, DSM-5, 2013).

Typically, the caregiver seeks frequent medical consultations, driven by a desire for attention, sympathy, or emotional validation. Meadow later outlined four essential diagnostic criteria for MSBP (Meadow R, Child Abuse Negl 2002; 26(5): 501–508):

1. The illness is fabricated or induced by the caregiver.

2. The child undergoes repeated medical evaluations without clinical justification, and the caregiver denies involvement.

3. Symptoms improve when the child is separated from the caregiver.

4. The caregiver’s motivation is to assume the sick role by proxy or to gain attention.

Publication History

Article published online:
22 September 2025