Acute nephritic syndrome and glomerulonephritis — structured clinical encounter

Task 1 — Establish the diagnosis and the glomerular source (3 minutes)

Confirm that this child has an acute nephritic syndrome, naming the four clinical components and explaining how the dysmorphic red cells and red-cell casts on microscopy establish a glomerular, rather than a lower-urinary-tract, source of bleeding. State why the two-week interval between the sore throat and the nephritis is the expected latent period for pharyngeal group A streptococcal infection. [1] [3]

Task 2 — Interpret the complement and confirm the cause (4 minutes)

Explain how the low C3 with a normal C4, together with the raised ASO and anti-DNase B, establishes post-streptococcal glomerulonephritis. State the single follow-up blood test you will arrange at six to eight weeks, the result you expect, and the finding that would contradict uncomplicated post-streptococcal GN and mandate renal biopsy. [2] [11]

Task 3 — Immediate and definitive management (4 minutes)

Outline your supportive-care plan, naming the loop diuretic and its dose for his oedema, the antihypertensive class you would start for his blood pressure, and the fluid and salt restriction. State the streptococcal eradication regimen, and explain clearly to the examiner why penicillin eradicates the strain but does not reverse the established glomerulonephritis. [1] [3]

Task 4 — Red flags, escalation and the family conversation (4 minutes)

State the features that would escalate this child to paediatric intensive care or dialysis (rapidly rising creatinine, oligoanuria, hypertensive emergency, pulmonary oedema). Explain to the parents, in language they can use, what post-streptococcal glomerulonephritis is, why more than 95 per cent of children recover fully, and why you will recheck the C3 and the urine in six to eight weeks and continue long-term follow-up of blood pressure and kidney function. [6] [8]