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.