A kidney infection, also called pyelonephritis, is a type of urinary tract infection (UTI). In most cases, UTIs are not serious and easily treated with antibiotics. However, frequent kidney infections can cause permanent damage to the kidneys. In most cases, a kidney infection is caused by bacteria that has moved into the kidneys. Your child may have had a bladder infection that wasn’t caught fast enough and moved into the kidneys.
Symptoms of a kidney infection may include high fever, diarrhea, and strong smelling or pinkish urine. If your child is toilet trained, nighttime bed-wetting may start or more frequent urination during the day. Your child may complain about trying to pee and not being able to. Listen for complaints of back or abdominal pain. Other symptoms can include fussiness, fatigue, vomiting, and loss of appetite. Sometimes the only symptom is a fever.
It is important to see your doctor right away if you think your child might have a kidney infection. Your doctor will examine your child to see if there is tenderness in the back or tummy. To diagnose a kidney infection, your doctor will need a urine sample to send for a culture. This will diagnose the presence of an infection, but a urine test can’t help your doctor distinguish between a kidney infection and bladder infection. Depending on the age of your child and level of sickness, your doctor may also order blood tests to look for signs of infection. Abnormal blood tests point to an infection that has spread to the kidneys rather than a simple bladder infection.
Symptoms of a kidney infection may include high fever, diarrhea, and strong smelling or pinkish urine.
Once an infection is diagnosed, the usual treatment is to prescribe antibiotics. It’s important to follow the prescribing instructions with the medication and give the whole course of antibiotics, even if your child perks up after a few days. Stopping antibiotics too soon can cause the infection to come back even stronger.
After the infection is cleared up, your doctor will run other tests to make sure there are no abnormalities in the urinary tract. This may include a kidney and bladder ultrasound to check for damage or abnormalities. Other possible tests include a VCUG (vesicourethrogram) to look at the anatomy of the kidneys, or a DMSA renal scan to look for scarring. The type of tests done will depend on your child and the type of infection.
Your doctor may also refer you to a specialist if your child is having frequent infections. If there are abnormalities, your child may simply outgrow them. In some cases, however, they may need to be corrected surgically.
Reviewed by Dr. Sara Connolly, January 2019
- Kidney infections can be serious, and if they are frequent they can cause permanent damage.
- As with other UTIs, a kidney infection is initially diagnosed through a urine sample and a physical exam.
- Mild kidney infections are easily treated with antibiotics.
- After the infection clears up, your doctor may want to run tests to check for abnormalities in the urinary tract.