Failure to thrive: a delayed presentation of congenital diaphragmatic hernia.

A toddler attended our emergency department with fever and cough. She was pale with mild work of breathing and an otherwise normal respiratory examination. She had intermittent vomiting, previously attributed to a cow's milk protein allergy, and was noted to be failing to thrive with faltering weight gain. She was found to have a severe iron deficiency anaemia. Chest radiograph showed a right mediastinal mass, confirmed on CT as a right posterior congenital diaphragmatic hernia (CDH).Iron deficiency resolved with supplementation. She had an uneventful elective surgical repair and straightforward recovery. Her weight gain improved significantly post-surgery.Late presentation of CDH can be challenging to diagnose as it can present with a variety of non-specific, acute or chronic symptoms and may also be incidental. It should be considered as a possible diagnosis in children presenting with severe unexplained iron deficiency anaemia and/or poor weight gain.