Poststreptococcal Glomerulonephritis (PSGN)

Key points about poststreptococcal glomerulonephritis

• poststreptococcal glomerulonephritis (PSGN) is a kidney disease
• PSGN can happen 10 to 14 days after a skin or throat infection caused by Streptococcus bacteria
• it is not caused by the bacteria itself but by the body's immune system responding to the infection
• the main symptoms are blood in the wee and sometimes swollen ankles or puffy eyes
• many tamariki develop high blood pressure for a few weeks
• if your child has PSGN, they will need regular blood pressure, weight and urine checks
• most tamariki (children) get better with no long-term complications
• it is very important to take your child to any follow-up appointments to make sure they make a full recovery

What is poststreptococcal glomerulonephritis?

PSGN is a kidney condition. It can happen 10 to 14 days after a throat or skin infection caused by Streptococcus (strep) bacteria. 

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The illustration shows a boy with medium-brown skin and short curly hair, wearing a pale shirt with the letters ‘KH’ on the chest. A simplified diagram of the urinary tract is drawn on the body, showing the kidneys, ureters, bladder, and urethra.

A circle highlights the left kidney, with dashed lines pointing to two enlarged cross-sections:

• The top circle is labelled Normal and shows a healthy kidney with clear inner structures and blood vessels.
• The bottom circle is labelled Post-streptococcal glomerulonephritis (PSGN) and shows the same kidney but with red, inflamed areas. A label reads: Inflammation inside the kidney.

At the top right is the KidsHealth logo with the website: kidshealth.org.nz

What do kidneys do? 

Kidneys are two small bean shaped organs that are the size of your fist. They’re located towards the back of the abdomen. Each kidney contains about a million filters, called glomeruli. Glomeruli do the job of removing waste and excess water from the blood to produce urine. The urine travels from the kidneys down 2 narrow tubes called the ureters. The urine is then stored in the bladder.  When your child does a wee, urine flows out of the body through the urethra, a tube at the bottom of the bladder. 

Causes of poststreptococcal glomerulonephritis

PSGN can happen 10 to 14 days after a skin or throat infection with the streptococcus bacteria. When your child's body tries to fight infection, their immune system makes antibodies. Antibodies help identify and destroy bacteria.

In tamariki with PSGN, this immune response to the infection causes inflammation and injury to the glomeruli (filters).  These injured glomeruli let blood cells and urine leak into the urine which is abnormal.  It can also make it hard for the kidneys to clean the blood and get rid of waste.  

How infectious is poststreptococcal glomerulonephritis?

You can’t ‘catch’ PSGN. PSGN happens from the body’s immune system response after a streptococcus infection. This could be a skin or throat infection. The strep infection that triggers PSGN can spread from one person to another.

Signs and symptoms of poststreptococcal glomerulonephritis

Blood and protein in the wee 

Tamariki can have blood in their wee (haematuria). This may make the wee dark or brown coloured. Sometimes it is only discovered after a urine test.

Tamariki may also have protein in their wee (proteinuria).

Puffiness around the eyes or the ankles

Tamariki may have swelling (oedema). Fluid collects in the tissues and can cause puffiness around the eyes or the ankles.

A change in how often they wee

Tamariki with PSGN may wee less often or stop weeing completely.

Headaches and tiredness

Tamariki can have high blood pressure (hypertension). This can cause headaches.

Tamariki may also be more tired. 

Diagnosing poststreptococcal glomerulonephritis

The health professional will examine your child and ask you about their symptoms. They will arrange blood and urine tests.

If the health professional thinks your child might have PSGN, your child will likely need to go to hospital.

The health professional will check your child's wee for protein and blood. Your child will get a blood test to check how well their kidneys are working and if they’ve had a recent strep infection. 

The health professional may do other tests to rule out other possible kidney conditions. 

Managing poststreptococcal glomerulonephritis

PSGN gets better on its own. Management focuses on relieving symptoms and trying to prevent complications.

Food and fluids

Tamariki with PSGN will need to have a low salt diet. Low salt helps reduce high blood pressure and swelling from fluid retention. The health professionals may put a limit on how much your child should drink each day.

Medicine

The health professional may give antibiotics to treat any strep bacteria still in the body.

Your child may need diuretic medicine to help their kidneys to get rid of salt and water.

Your child may also need extra medicine to bring their blood pressure down. Tamariki can usually go home from hospital once their blood pressure is normal. If they are on blood pressure medicine, they may need to stay on this a bit longer once they go home.

How long poststreptococcal glomerulonephritis lasts

Most tamariki make a full recovery within a few weeks.

The blood you can see in the wee is usually gone in a couple of weeks. But, urine tests may still show blood in your child's wee for up to 2 years.

The high blood pressure comes down over several weeks. Some tamariki may need to take medicine for their blood pressure.

Ongoing checks after having poststreptococcal glomerulonephritis

Your child will still need regular checks after leaving hospital. They will continue to have their blood pressure, weight and wee checked.

It is important to go back to a health professional if PSGN symptoms return after the checks finish.

If you're worried about your child's health at any stage, see a health professional.

Possible complications of poststreptococcal glomerulonephritis

Most tamariki make a complete recovery from PSGN. But, for a small number of tamariki, the disease will cause longer term kidney injury. 

Health professionals will continue to look out for:

• continuing high blood pressure (hypertension)
• poor kidney function
• continuing protein in the wee (proteinuria)
• headaches and seizures

Caring for your child with poststreptococcal glomerulonephritis at home

After your child goes home from hospital it is important they take their medicine. It is also important that you take your child to their regular checkups. Your child will have regular blood pressure, weight and urine checks.

Preventing poststreptococcal glomerulonephritis

Treating strep throat or skin infections early with antibiotics may prevent PSGN. If your child has a throat or skin infection, take them to a health professional to get checked. If they are diagnosed with a strep infection take the full course of antibiotics as prescribed.