New onset unilateral arm swelling in a child with periorbital oedema

An 8 year old girl was referred to the paediatric assessment unit with four weeks of puffy eyes following a suspected viral upper respiratory tract infection. Her facial swelling had exacerbated in the two weeks before this presentation, and her mother had noticed that her trousers no longer fitted because of abdominal and thigh swelling. The child was eating normally with normal bowel movements, and was afebrile.

On examination, generalised oedema was noted, including periorbital and facial swelling, and a distended, non-tender abdomen. On chest auscultation, there were some fine basal crepitations bilaterally. The child’s left forearm was notably more swollen …