Acute nephritic syndrome and glomerulonephritis — branching viva

Stem 1 — Six-year-old with cola-coloured urine (5 minutes)

A six-year-old boy presents with two days of smoky brown urine and morning periorbital puffiness. He had a sore throat two weeks ago. His blood pressure is at the 95th percentile and his urinalysis shows blood and protein with dysmorphic red cells and casts. ^{[3] [6]}

Branch A (examiner): Define the acute nephritic syndrome and name its four components. Why is this almost certainly post-streptococcal glomerulonephritis? ^{[1] [3]}

Branch B (examiner): What will his serum complement show, and by when should the C3 normalise? What follow-up blood test confirms the diagnosis, and what result would force you to change the diagnosis? ^{[2] [11]}

Branch C (examiner): Outline your supportive management. Name the eradication regimen, and explain clearly why penicillin does not reverse the glomerulonephritis itself. ^{[3] [6]}