Suspicion of Munchausen syndrome by proxy with a child's presentation of undernutrition, scurvy, and an apparent Avoidant Restrictive Food Intake Disorder.

Purpose: Avoidant Restrictive Food Intake Disorder (ARFID) was recently characterized in the DSM-5 classification. Potential differential diagnoses remain poorly reported in the literature. Our purpose was to present a possible Munchausen syndrome by proxy with undernutrition and scurvy, presenting as ARFID in a child.

Methods: We describe here a case of an 8-year-old boy who presented with severe undernutrition (BMI = 11.4) and scurvy leading to joint pains. The boy had had a very selective diet since early childhood, and his condition required hospitalization and enteral refeeding. Because of his specific eating behaviour, an ARFID was initially suspected. However, observation of the mother-child relationship, analysis of the child's eating behaviour, and retrospective analysis of his personal history suggested that this was not a true ARFID, and that the selective eating behaviour had probably been induced by the mother over many years, who probably maintained a low variety diet.

Conclusion: Munchausen syndrome by proxy is a difficult differential diagnosis, which may also affect patients with ARFID symptoms, which may also present in the affected child as apparent ARFID.

Level Of Evidence: Level V, descriptive study.