Pediatric emergency medicine trisk 2895 2895

countries. Many organisms including Staphylococcus sp ., Pneumococcus,
Salmonella typhi, Klebsella pneumoniae, and E. coli may be causative.
In regards to streptococcal-related nephritis, the latent period from
infection to acute poststreptococcal glomerulonephritis (APSGN) is
generally 1 to 3 weeks after pharyngitis and 3 to 6 weeks with skin
infections. It most often affects children aged 4 to 14 years old, and rarely
occurs in children less than 2 years old. Males are more often affected. In
recent decades, the prevalence of APSGN has declined in most
industrialized nations, although it persists at high rates in some developing
countries.
The clinical presentation of APSGN may vary from asymptomatic
microscopic hematuria to an abrupt onset of nephritic syndrome.
Subclinical APSGN is four to five times more common than an acute
clinical presentation, which can be associated with gross hematuria,
proteinuria, oliguria, edema, and hypertension. Hypertension can be severe
and evolve into hypertensive emergency, which typically affects the CNS in
children. Symptoms include headache, seizure, and encephalopathy.
Clinical assessment. A detailed history and physical examination should
be completed when there is a suspicion of APSGN. The color and quantity
of urine output should be assessed by history. A history of a preceding
streptococcal infection may be present, although the infection may not have
been identified at the time. The physical examination should assess for the
consequences of APSGN. The patient should be evaluated for signs of fluid
overload including hypertension, and the signs and symptoms of
hypertensive crisis should be addressed.
Laboratory studies during a typical episode of APSGN reflect a nephritis
with activation of the alternative complement pathway. Serum studies may
demonstrate reduced renal function. Associated electrolyte abnormalities
include hyponatremia, reflecting an inability to excrete water, and
hyperkalemia. The majority of patients have a low C3 complement, and a
normal C4 complement. The C3 level normalizes in 6 to 8 weeks. If the C3

remains depressed after 3 months or the C4 is low, diagnostic
considerations include chronic forms of glomerulonephritis, including
membranoproliferative glomerulonephritis (MPGN) and lupus nephritis. If
the complement levels are normal at presentation, APSGN is less likely, and
IgA nephropathy would be a consideration.