Developmental regression as a presenting feature of severe nutritional rickets

Abstract Background: Rickets is a disorder of defective mineralisation of the growth plate. Vitamin D deficiency remains the leading cause of nutritional rickets worldwide despite developed countries having supplementation policies in place. Case presentation: We present the case of a 3.5-year-old breastfed boy who presented with dental abscess when a history of developmental regression was noted. Clinical assessment revealed hypotonia, poor growth and stunting. Biochemistry identified hypocalcaemia (1.63mmol/L, [normal range (NR) 2.2-2.7mmol/L]), severe vitamin D deficiency (25hydroxyvitamin D 5.3nmol/L, [NR>50nmol/L]) with secondary hyperparathyroidism (Parathormone 158pmol/L, [NR 1.6-7.5pmol/L]) and rickets on radiographs. Growth failure screening suggested hypopituitarism with central hypothyroidism and low IGF1 at baseline, however, dynamic tests confirmed normal axis. Management included nasogastric nutritional rehabilitation, cholecalciferol and calcium supplementation and physiotherapy. A good biochemical response in all parameters was observed within weeks and reversal of developmental regression by 3 months from treatment. Conclusion: Developmental regression as a presentation of nutritional rickets is rare and requires a high index of suspicion. Nutritional rehabilitation and appropriate supplementation promptly restores motor milestones.