Acute poststreptococcal glomerulonephritis: the most common acute glomerulonephritis.

On the basis of strong research evidence, the prevalence of poststreptococcal glomerulonephritis (PSGN) is decreasing worldwide, although it still remains the leading cause of glomerulonephritis in children. The overall decrease in prevalence of PSGN has been mainly driven by a significant decrease in pyoderma seen in the last half-century, such that postpharyngitic PSGN is most commonly seen in developed nations. On the basis of primarily consensus because of a lack of relevant clinical studies, the latency period between streptococcal infection and the development of nephritis is a hallmark of PSGN, with this period lasting 1 to 2 weeks with pharyngeal infections or 2 to 6 weeks with skin infections. Concurrent infectious and nephritis symptoms should elicit further suspicion of other causes of glomerulonephritis. On the basis of expert opinion, PSGN is one of a handful of nephritic disorders with hypocomplementemia (low C3 level). The decrease in C3 is found in more than 90% of PSGN cases and is typically seen earlier than an increase in antistreptolysin O titers. Measuring C3 and C4 may also be helpful in the evaluation of other causes of acute nephritis. On the basis of primarily consensus because of a lack of relevantclinical studies, the main sequelae of PSGN (hypertension, edema,gross hematuria, and impaired renal function) are greatest in thefirst 7 to 10 days of disease. Therefore, this period requires themost vigilance for adverse effects. On the basis of some research evidence and consensus, the most effective treatment of hypertension and edema in PSGN is loop or thiazide diuretics, which may also address hyperkalemia. Angiotensin-converting enzyme inhibitors or angiotensin receptor blockers may be effective in hypertension control but carry the risk of hyperkalemia and temporarily impairing recovery of renal function. On the basis of some research evidence and consensus, the prognosis for PSGN, even long term, is good. Despite being the most prevalent of the childhood glomerulonephritides, it often does not cause chronic kidney disease, but persistent microscopic hematuria and proteinuria may be seen in less than 10% of patients.