Lesson of the Week: Hypocalcaemic stridor and infantile nutritional rickets

Abstract

Nutritional deficiency of vitamin D is considered to be a rare cause of rickets in industrialised countries, mainly because vitamin D is added routinely to formula feeds for infants.1 2 Human breast milk, however, may be deficient in vitamin D, and exclusively breast fed infants who have not received vitamin supplements are at risk. Otherwise well nourished infants may not have the obvious or typical bony deformities of rickets but may present with the symptoms of hypocalcaemia. We describe two infants who presented with stridor and intermittent sudden airway obstruction due to laryngospasm. Both infants had severe hypocalcaemia due to nutritional deficiency of vitamin D. ### CASE 1 A 5 month old black boy weighing 7.5 kg was taken to the accident and emergency department at Queen Elizabeth Hospital for Children with a one month history of intermittent laboured and noisy breathing. The boy's respiratory distress had often been accompanied by generalised rigidity, convulsions, and cyanosis and had usually occurred when he was crying. He was taken to the hospital because he had become apnoeic at home and had been given mouth to mouth resuscitation by his mother. Just after he was …