Key points to remember about poststreptococcal glomerulonephritis
What is poststreptococcal glomerulonephritis?PSGN is a kidney disease that can happen 10 to 14 days after a throat or skin infection caused by Streptococcus (a type of bacteria). Show
What causes poststreptococcal glomerulonephritis?Your child's infection-fighting (immune) system causes PSGN. When your child's body tries to fight infection, their immune system makes antibodies. Antibodies help identify and destroy bacteria. In children with PSGN, the dead bateria and antibodies become trapped in the filters of the kidneys (glomeruli). This causes inflammation, which slows down the filters of the kidneys, making it harder for them to make urine and get rid of the waste. How infectious is poststreptococcal glomerulonephritis?You cannot 'catch' PSGN as it is caused by the body's own infection-fighting (immune) system. But, streptococcal infections (either from the skin or throat) can spread from person to person. What are the signs and symptoms of poststreptococcal glomerulonephritis?These can vary. Some children may have no symptoms, or they may:
How is poststreptococcal glomerulonephritis diagnosed?Your child's doctor may diagnose your child with PSGN after checking your child's signs, symptoms, and blood and urine tests. If your family doctor thinks your child might have PSGN, your child will need to go to hospital. Doctors will check your child's wee for protein and blood. Your child will also get a blood test to check kidney function, signs of a recent streptococcal infection and the effect of the infection on the immune system. Doctors may also check for other things in the blood to rule out other conditions and different causes of glomerulonephritis. What is the treatment for poststreptococcal glomerulonephritis?PSGN gets better on its own, so treatment focuses on relieving symptoms and trying to prevent complications. Your child will need to have a low salt diet. The doctor may give your child a maximum amount they can drink each day. Your child may need medicine to bring their blood pressure down. They may also need medicine to encourage their kidneys to get rid of salt and water. The doctor will usually give your child antibiotics to treat any streptococcus bacteria left in their body. Your child can usually leave hospital once their blood pressure is back to normal, or controlled with medicine. How long could poststreptococcal glomerulonephritis last?Most children make a full recovery within a few weeks. The blood you can see in the wee is usually gone in 2 weeks. But, urine tests may still show blood in your child's wee for up to 2 years. The high blood pressure comes down in about 4 weeks. Some children may need to take medicine for their blood pressure. What checks will my child need after having poststreptococcal glomerulonephritis?Your child will continue to have blood pressure, weight and urine checks once they've left hospital. Once these checks have finished, it is important to go back to your family doctor if you notice any PSGN signs and symptoms again. If you're worried about your child's health at any stage, see your family doctor. What are the possible complications of poststreptococcal glomerulonephritis?Most children make a complete recovery. But, for a small number of children, the disease will continue and for an even smaller number of children the disease may get worse. The main things your doctor will look out for are:
How can I care for my child with poststreptococcal glomerulonephritis at home?It is important your child takes any prescribed medicine. It is also important you take your child to checkups with the doctor. Your child will have blood pressure, weight and urine checks. How can poststreptococcal glomerulonephritis be prevented?If streptococcal skin or throat infections are discovered early, they can be treated with antibiotics, which may prevent the development of PSGN. References Boon, N., Davidson, S. (eds). 2006. Davidson's principles and practice of medicine. 20th Edition. Edinburgh: Churchill Livingston. Kliegman, R., Behrman, R., Jenson, H., Stanton, B. (eds). 2007. Nelson textbook of pediatrics. 18th Edition. Philadelphia, PA: Saunders. Starship Children's Health. November 2021. Clinical Guidelines: Glomerulonephritis. https://www.starship.org.nz/for-health-professionals/starship-clinical-guidelines/g/glomerulonephritis/. [Accessed 17/03/2022] UpToDate: PostStreptococcal Glomerulonephritis. https://www.uptodate.com/contents/poststreptococcal-glomerulonephritis. [Accessed 17/03/2022] Wong W, Morris MC, Zwi J. May 2009. Outcome of severe acute post-streptococcal glomerulonephritis in New Zealand children. Pediatric Nephrology. 24(5):1021-6. Wong W, Lennon DR, Crone S, Neutze JM, Reed PW. June 2013. Prospective population-based study on the burden of disease from post-streptococcal glomerulonephritis of hospitalised children in New Zealand: Epidemiology, clinical features and complications https://pubmed.ncbi.nlm.nih.gov/23782011/. [Accessed 17/03/2022] Which test is important in the investigation of post streptococcal disease?ASO titer is the most frequently used test, while the most sensitive is the streptozyme test; which includes measuring the titers of all the antibodies mentioned above. ASO titers can be falsely low in patients treated with antibiotics for streptococcal infections.
What diagnostic tests are used to confirm the diagnosis of glomerulonephritis?These tests may be an X-ray, an ultrasound exam or a CT scan. Kidney biopsy. This procedure involves using a special needle to extract small pieces of kidney tissue to look at under a microscope. A biopsy is used to confirm a diagnosis and to assess the degree and nature of tissue damage.
Which of the following laboratory findings is most consistent with Poststreptococcal glomerulonephritis?The most consistent and classic diagnostic finding is the presence of glomerular subepithelial electron-dense immune-type deposits, often referred to as humps (see the image below). The deposits are discrete and are commonly found on the part of the glomerular basement membrane overlying the mesangium.
Which laboratory test is typical for acute post streptococcal glomerulonephritis?Recent poststreptococcal infection is most commonly demonstrated by serologic markers for elevated antibodies to extracellular streptococcal antigens. The streptozyme test, which measures 5 different streptococcal antibodies, is positive in more than 95% of patients with APSGN due to pharyngitis.
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