Acute post-streptococcal glomerulonephritis is a rare kidney disease that develops after infection with a specific strain of the Streptococcus bacterium. According to the Children’s Hospital of Boston, acute post-streptococcal glomerulonephritis is one of the most common causes of glomerulonephritis in children. Although this condition can affect people of any age, it is most common among children who are 6 to 10 years old.
Function
Glomerulonephritis is an inflammation of the glomeruli in the kidney. Glomeruli are small structures that direct the blood supply to the nephrons, the units responsible for filtering the blood and removing waste products into the urine. When the glomeruli become inflamed, it impairs the kidney’s ability to filter the blood. This causes the presence of blood and protein in the urine.
Causes
Acute post-streptococcal glomerulonephritis occurs after a recent infection with group A beta hemolytic streptococcus bacteria. Group A strep is the bacteria that causes strep throat, as well as cellulitis, a skin infection. According to Medline Plus, post-strep glomerulonephritis can occur 1 to 2 weeks after an untreated throat infection or about 3 to 4 weeks after cellulitis.
Symptoms
According to the Merck Manuals, about half of patients with post-streptococcal glomerulonephritis do not develop symptoms. Of those who do, the first symptom that develops is edema, or swelling. This occurs as the kidney becomes damaged and loses its ability to process urine, leading to fluid retention. The swelling first becomes apparent in the face and as puffiness around the eyes. As the kidney becomes more damaged, high blood pressure develops, which can cause headaches and blurry vision.
Identification
Apart from the history of recent strep infection and the symptoms of glomerulonephritis, lab work can help identify children with post-streptococcal glomerulonephritis. Recent strep infection can be confirmed with a blood test called ASO titer, which measures the presence of antibodies against the strep bacterium. Blood test can also confirm if there is damage to the kidneys. Another useful tests is a urinalysis to assess the presence of blood and protein in the urine, another indication of kidney damage. If the diagnosis is still in doubt, a kidney biopsy may be necessary.
Treatment
There is no specific treatment for post-streptococcal glomerulonephritis because most children recover from this condition on their own. This recovery may take weeks or months. In the meantime, children may need medication to treat the high blood pressure or the swelling. A low-salt diet also helps during the recovery phase.
