Maternal Orthorexia Nervosa Causing Severe Ketoacidosis and Methylmalonic Acidura in Her Offspring

Introduction: Orthorexia Nervosa (ON) is an eating disorder describing patients with obsession for healthy food, in contrast to patients with anorexia and bulimia who worry about its quantity. ON may lead to a state of starvation due to strict diets and shortage of essential nutrients leading to various medical complications as seen in anorexia. To-date, only anecdotal cases on ON in adults were reported. We report for the first time a baby with episodes of apathy and severe ketoacidosis. History of the baby`s and his mother`s nutrition led us to suspect ON in the mother causing his critical condition.

Case report: A 17-months-old baby presented with few days history of lethargy and refusal to eat after an attempt of weaning breastfeeding. He had been mainly breastfed and rarely consumed solid food. A detailed dietary history revealed that the mother ate only vegan diet during nursing and provided her baby a strict "vegan, healthy uncooked diet omitting animal products and fortified babys` formulas". The baby was lethargic, pale, hyperpneic, had hypotoia with hyperrexflexia. His growth centiles were below the 3^rd percentile. He could not role over nor sit unassisted. Laboratory studies revealed pancytopenia and severe ketoacidosis. Clinical and biochemical features suggested an inborn error of metabolism (IEM). Urinary organic acids revealed severe ketoacidosis and methylmalonic aciduria. Slow refeeding program including multiple vitamins and vitamin-B12 resulted in resolution of all abnormalities.

Conclusion: We describe for the first time ON in a mother causing life-threatening disorder in her child. We designate this condition as "Maternal ON" similar to the notion of "Maternal phenylketonuria" (PKU) wherein high phenylalanine levels in a PKU mother who does not keep restricted diet, harms her offspring. Pediatricians and dieticians should be aware to Maternal ON mimicking IEM presenting as growth and development delay and/or severe metabolic abnormalities.