Purpose Avoidant restrictive food intake disorder (ARFID) was recently characterized, according to the DSM-5 classification, as a feeding and eating disorder (FED). However, ARFID remains poorly known by most pediatricians, but also by psychiatrists and primary care professionals. Despite the fact that patients with ARFID generally have a higher BMI than patients with anorexia nervosa, our purpose was to highlight the fact that they may present severe nutritional deficiencies and major somatic complications when the diagnosis is delayed. Method We describe here a case of a 16-year-old boy who presented with severe undernutrition (BMI = 11.5) leading to Ogilvie's syndrome, which resolved with enteral refeeding. Because of undernutrition, very bad dental condition, and encopresis, some physicians wrongly suspected child neglect, but retrospective analysis of his personal history revealed a longterm FED and sensory specificities that led to the final diagnosis of an ARFID-autism spectrum disorder (ASD) association. A literature review was conducted on the ARFID somatic complications. ConclusionThe training of health professionals in the clinical forms of pediatric FED, including ARFID, is necessary, to promote early diagnosis and prevent poor nutritional outcomes. In this case the association of ARFID-ASD and the delay in access to specialized care favored by the disadvantaged social environment led to severe gastrointestinal complications. Level of evidence V, descriptive study.

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