A child with history of recurrent throat infrctions presents with hematuria and proteinuria with the last infection being 3 weeks back. The diagnosis is-
**Core Concept**
Post-streptococcal glomerulonephritis (PSGN) is an immune complex-mediated glomerulonephritis that occurs following a streptococcal infection, such as streptococcal pharyngitis. The pathogenesis involves the deposition of antigen-antibody complexes in the glomeruli, leading to inflammation and renal damage.
**Why the Correct Answer is Right**
The correct answer is related to PSGN, which is a known complication of streptococcal pharyngitis. The mechanism involves the formation of immune complexes, which are deposited in the glomeruli, triggering an inflammatory response. The clinical presentation of PSGN includes hematuria, proteinuria, and hypertension, often occurring 1-3 weeks after the initial infection. The renal biopsy typically shows mesangial proliferation and capillary wall thickening.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because IgA nephropathy, also known as Berger's disease, is a different type of glomerulonephritis characterized by IgA deposition in the glomeruli, often presenting with hematuria after an upper respiratory tract infection. However, it does not typically follow a streptococcal infection.
**Option B:** This option is incorrect because Henoch-Schönlein purpura (HSP) is a vasculitis that affects small blood vessels, often presenting with purpura, joint pain, and gastrointestinal symptoms. While HSP can cause renal involvement, it is not typically associated with a history of streptococcal pharyngitis.
**Option C:** This option is incorrect because Minimal Change Disease (MCD) is a type of nephrotic syndrome characterized by loss of foot processes on electron microscopy, often presenting with massive proteinuria and hypoalbuminemia. MCD is not typically associated with a history of streptococcal infection.
**Option D:** This option is incorrect because Goodpasture's syndrome is an autoimmune disease characterized by anti-GBM antibodies, often presenting with rapidly progressive glomerulonephritis and pulmonary hemorrhage. Goodpasture's syndrome is not typically associated with a history of streptococcal infection.
**Clinical Pearl / High-Yield Fact**
PSGN often presents with a characteristic "hump" on the creatinine curve, with a delay in the rise of serum creatinine after the initial infection. This is due to the time it takes for the immune complexes to deposit in the glomeruli and cause renal damage.
**Correct Answer:** . Post-streptococcal glomerulonephritis