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

SELF-DIAGNOSIS NEEDS LAB TEST CONFIRMATION BEFORE ANTIBIOTIC RX

Question: One of my kids was diagnosed with strep throat last week and is on antibiotics. Now my husband and I have sore throats. Is it necessary to do the throat culture to make this diagnosis? Can’t the doctor tell by looking? Shouldn’t I just be able to call the office and get an antibiotic?

Answer: Streptococcal pharyngitis -- strep throat -- can occur in anyone of any age. It is more common in children, and the incidence of strep throat peaks in the winter months. This infection is spread by direct contact from one person to another. The bacteria are spread through saliva and nasal secretions.

If, indeed, you currently have strep throat, it’s highly possible that you got it from your child. However, you can also become exposed to the strep bacteria at the grocery store, church, movie theaters, shopping malls or any other place where people gather.

Strep bacteria can cause infection within two to five days of exposure. The primary site of the infection is usually the throat. The symptoms tend to start abruptly and include sore throat, fever, headache and, sometimes, nausea. There may be swollen lymph nodes (glands) in the neck that are tender to the touch. It is also typically very painful to swallow. Like many other infections, however, not everyone has the “classic” presentation of strep. Sometimes, for instance, the onset is gradual, and the throat is not very sore.

Because the presentation can vary, it is important to evaluate a sore throat properly. Many physician’s offices, urgent care centers and hospital emergency departments can perform a rapid antigen strep test. This takes about ten minutes to run. If it is positive, meaning that strep is present, your doctor will likely start you on antibiotics. However, if the results are negative, there is still about a 15 percent chance that you have a strep infection that was missed by the rapid antigen test. This is why many doctors follow up a negative rapid test with a more accurate -- but slower -- throat culture. You may have to wait a couple of days before results come back. There is also a newer Rapid DNA test which is as accurate as a throat culture but takes a few hours rather than a few minutes to produce results. It is not yet widely available.

When you are diagnosed with strep throat, it is important that you are treated with antibiotics. This can prevent complications like rheumatic fever and kidney problems. However, if you have the more common type of sore throat that is caused by a virus, antibiotics will do you no good. It is not possible to differentiate between strep throat and a viral infection either by undergoing a doctor’s physical exam or self-diagnosing based on your child’s illness. That’s why your doctor wants to do a strep test before prescribing antibiotics. Inappropriate prescribing of antibiotics does more harm than good.

When there is strep throat or any contagious illness in the family, good hand washing becomes more important that ever. Also, it is a good idea to go over and above your usual cleaning efforts by -- once or twice a day -- using a disinfectant to wipe off the doorknobs, remote control, computer keyboard and light switches. This helps keep all types of germs (bacteria, viruses, fungi, etc.) to a minimum and helps the non-infected family members stay well.

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.