An infant with respiratory distress

A 4 month old African girl presented to the accident and emergency department with a two day history of fever, cough, and poor feeding. She was born full term at a weight of 3000 g. She had no neonatal complications. She was exclusively breast fed and her mother had no history of serious illness. On examination, she had fever, tachypnoea, and tachycardia. Her oxygen saturation was 96% on air. Fine crepitations were heard at the bases of her lungs. A gallop rhythm was detected on cardiac auscultation. Her liver was 2 cm palpable. She had swollen but non-tender wrists. Her full blood count and liver function tests were normal except for an alkaline phosphatase of 942 U/l. Her calcium was 1.5 mmol/l and phosphate 2.16 mmol/l. Radiography of the chest and right wrist was performed (fig 1⇓).

• 1 What are the radiological findings?

• 2 What additional investigations should be requested?

• 3 What is the most likely diagnosis in this patient?

• 4 How should the condition be treated?