FAMILY MEDICINE® COLUMN

By Martha A. Simpson, D.O., M.B.A.
Associate Professor of Family Medicine
Ohio University College of Osteopathic Medicine

KIDS USUALLY RECOVER FULLY FROM STREP-RELATED KIDNEY FAILURE

Question: My child was recently diagnosed with kidney problems due to a strep throat. I was surprised by this as I never took her to the doctor for a sore throat, though she did have one. It went away on its own. Now she has these kidney problems. Can you explain what is going on and what I should expect.

Answer: From your description it sounds like your daughter has a condition -- called post-streptococcal glomerulonephritis -- that produces acute kidney failure following a strep infection. In addition to the strep throat that your daughter had, there are several different types of strep infections that can also cause this disorder. Two of these, which manifest themselves primarily as skin problems, are scarlet fever and impetigo.

In post-streptococcal glomerulonephritis, immune complexes produced by your body’s reaction to the strep infection become trapped in structures in the kidney called glomeruli. These look like tiny balls of yarn and are composed of small blood vessels that filter the blood to form urine. When the immune complexes get caught up in the glomeruli, they become inflamed and are less efficient in their filtering and excreting functions.

While post-streptococcal glomerulonephritis can occur in people of any age, it is most common in children between 6 and 7. It usually develops 10 to 14 days after the initial infection with the streptococcus bacteria. This disorder is now relatively uncommon in developed countries due to the widespread use of antibiotics to treat the original strep infection. Today it is seen most often in cases like your daughter’s, where a strep infection is undiagnosed and, therefore, untreated.

When a person with post-strep glomerulonephritis is first seen in the family physician’s office, there are typically some telltale “presenting symptoms.” These include dark or bloody urine, decreased urine output and swelling. The swelling is usually of the face or eyes. Sometimes there is joint pain and stiffness as well. On physical exam the physician may also find high blood pressure. Usually lab tests on blood and urine samples are sufficient to make the diagnosis. In some cases, a biopsy of the kidney may be needed if the diagnosis is in question.

There is no specific treatment for this condition. The symptoms such as high blood pressure and swelling are treated with appropriate medications. Occasionally, antibiotics are given if it is felt that bacteria are still present. In children, like your daughter, it is usually a self-limiting disorder and resolves completely in four to six weeks.

When post-streptococcal glomerulonephritis occurs in adults, especially those with other underlying health problems, it can be much more serious. In some cases it can lead to heart failure and permanent kidney failure. That’s why I think it’s important for adults to seek medical care when they get a sore throat to be sure it isn’t strep. Remember, you never “outgrow” strep throat.

Family Medicine® is a weekly column. To submit questions, write to Martha A. Simpson, D.O., M.B.A., Ohio University College of Osteopathic Medicine, P.O. Box 110, Athens, Ohio 45701, or via e-mail to readerquestions@familymedicinenews.org. Medical information in this column is provided as an educational service only. It does not replace the judgment of your personal physician, who should be relied on to diagnose and recommend treatment for any medical conditions. Past columns are available online at www.familymedicinenews.org.