Poststreptococcal Glomerulonephritis (PSGN)

Key points about poststreptococcal glomerulonephritis

• poststreptococcal glomerulonephritis (PSGN) is a kidney disease that can happen 10 to 14 days after a skin or throat infection
• it is not caused by the bacteria itself but by the body's infection-fighting (immune) system
• the main symptoms are blood in your child's wee and swollen ankles or puffy eyes
• your child will need regular blood pressure, weight and urine checks
• your child will need a blood test to check kidney function
• most tamariki (children) - 95% 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 disease that can happen 10 to 14 days after a throat or skin infection caused by Streptococcus (a type of bacteria).

The urinary tract and how it works

The urinary tract is the kidneys, ureters, bladder, and urethra.

The kidneys filter and remove waste and 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. The opening of the urethra is at the end of the penis in boys and in front of the vagina in girls.

Causes of 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 tamariki with PSGN, the dead bacteria 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.

Signs and symptoms of poststreptococcal glomerulonephritis

These can vary. Some tamariki may have no symptoms, or they may have the following symptoms.

Blood and protein in the wee 

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

Your child may also have protein in their wee (proteinuria).

Puffiness around the eyes or the ankles

Your child 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

Your child may wee less often or stop weeing completely.

Headaches and tiredness

Your child may have high blood pressure causing headaches (hypertension).

Your child may also be more tired. 

Diagnosing poststreptococcal glomerulonephritis

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.

Managing 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 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 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 tamariki may need to take medicine for their blood pressure.

Ongoing checks 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.

Possible complications of poststreptococcal glomerulonephritis

Most tamariki make a complete recovery. But, for a small number of tamariki, the disease will continue and for an even smaller number of tamariki the disease may get worse. The main things your doctor will look out for are:

• continuing high blood pressure (hypertension)
• poor kidney function
• continuing protein in the wee (proteinuria) which may not cause obvious symptoms
• headaches and seizures

Caring for your 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.

Prventing poststreptococcal glomerulonephritis

If streptococcal skin or throat infections are discovered early, they can be treated with antibiotics, which may prevent the development of PSGN.