Kidney Infections In Children

Key points about kidney infections in children 

• the most common cause of a kidney infection is when a UTI spreads from the bladder to the kidney
• this causes inflammation to develop in the kidney
• kidney infections can make tamariki unwell 
• the treatment for a kidney infection is antibiotics 
• if you are concerned that your child has a UTI or kidney infection, take them to see a healthcare professional as soon as possible

What is a kidney infection?

A kidney infection, also called pyelonephritis, is a type of urinary tract infection (UTI). It happens when a bacterial UTI spreads from the bladder to the kidney. This causes inflammation in the kidney.

What is the urinary tract and how does it normally work?

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.

Front and side view of the female urinary tract

Front and side view of the male urinary tract

What are the symptoms of a kidney infection in children?

Symptoms of a kidney infection can include:

• fever (temperature over 38 degrees Celsius)
• vomiting
• poor feeding or low appetite
• pain when doing a wee 
• tummy pain
• lower back pain 
• shivering
• tiredness and drowsiness 
• weeing more than usual 
• blood in the wee

When should I take my child to see a doctor?

Kidney infections can make pēpi and tamariki very unwell. If your child has any of the above symptoms, they may have a kidney infection and need to see a health professional as soon as possible.

If your child has a UTI  and is not improving while on antibiotics, take them back to a health professional.

How is a kidney infection diagnosed? 

If you think your child has a UTI or a kidney infection, take them to the health professional. The health professional will talk to you about your child's symptoms and check your child. 

Your child will need to give a urine sample. Depending on how old your child is, there are different ways to get this sample. 

See the KidsHealth page on urine testing for more information.

Your child may need other tests such as a blood test or scan. Your child may need to go to hospital if they are more unwell or need more specialist care.

What is the treatment for a kidney infection?

A kidney infection can make tamariki very unwell, and it is important that they see a health professional and get treatment as soon as possible.

Antibiotics 

Antibiotics are the treatment for a kidney infection. Most tamariki can take their antibiotics at home. It is important that your child takes the medicine as directed.

When tamariki are very unwell with a kidney infection, they may need to go to hospital to have antibiotics into the vein through an IV line. 

Drinking more fluids

It’s important that your child stays well hydrated. Encourage them to drink plenty of fluids.

Paracetamol if needed

You can give pain relief (paracetamol) if your child is in discomfort or miserable with a fever. You must follow the dosage instructions on the bottle. It is dangerous to give more than the recommended dose.

Some pēpi and tamariki need to go to hospital

Pēpi and tamariki with a UTI or kidney infection may need to go to hospital if they:

• are very young - under the age of 3 months
• are very unwell
• can’t take antibiotics by mouth 
• are dehydrated and having trouble drinking enough fluids 
• have a condition that affects their kidneys or urinary tract

They may need intravenous antibiotics given through an IV line. If they can’t drink enough fluids, they may also need fluids given through their IV line. 

See the KidsHealth page on IV lines for more information.

Can you prevent a kidney infection from happening?

Not all kidney infections can be prevented, but some things may help prevent them from happening. 

Treating UTIs early

If your child develops signs or symptoms of a bladder infection, take them to a health professional as soon as possible. Starting treatment early for a bladder infection can help to prevent it from spreading to the kidneys.

See the KidsHealth page on urinary tract infections for more information. 

Treating constipation

Tamariki who have constipation are at higher risk of developing a UTI. See your health professional if your child is constipated so they can discuss treatments with you. 

See the KidsHealth page on constipation for more information.

Drinking enough fluids

Encourage your child to drink plenty of water, especially during hot weather. 

Good bathroom habits

Encourage your child to go to the toilet regularly. Teach them to go as soon as they feel the need. If tamariki hold on for a long time, they have a higher chance of developing a UTI. 

Encourage your child to sit properly on the toilet with their feet on a stool so that they empty their bladder completely.

Teach girls to wipe their bottoms from front to back rather than back to front. This reduces the spread of germs from the bowel to the opening of the urethra.

Will my child’s kidney infection come back?

UTIs can happen again. If your child gets frequent UTIs, they may need further tests to work out why this is happening. Your child may need to have a scan of the urinary tract to check for any issues.

Chronic pyelonephritis

Chronic pyelonephritis, or chronic kidney infection, can happen when tamariki get frequent kidney infections. This usually happens if there is a problem with the urinary tract. If your child gets more than one kidney infection, they may need further tests, such as a scan of the bladder and kidneys.

What sort of scans might my child need? 

Different types of scans can look at the urinary tract. For information about these tests, see the following KidsHeallth pages.

Renal ultrasound scans
MCU (micturating cysto-urethrogram)
Nuclear medicine kidney scans

Can complications happen from a kidney infection?

Most pēpi and tamariki with a kidney infection make a full recovery if their infection is treated promptly. Rarely complications may happen after a kidney infection. Possible complications include damage to the kidney and spreading of the infection into the bloodstream. 

If your child gets chronic kidney infections, this can lead to scarring of the kidneys. If the kidneys become scarred, they may not be able to recover and function properly.