Medical Myth #5: Strep Throat

Another Medical Myth is the diagnosis and treatment of strep throat. Here is a GREAT summary written by Dr. Newman and some very good comments. The excerpts below are from a carefully researched book: Hippocrates’ Shadow by Newman. As always share your thoughts.

How do we diagnosis strep throat?

physical exam: “The signs and symptoms of strep throat have been exhaustively studied, and from this research we know that there are four important markers of strep throat infections: tender lymph nodes, fever, visible pus on the tonsils, and absence of a cough. When patients have all four of these characteristics, the chance that they have a strep throat infection is about 50 percent. But when they have zero, one, or even two of these characteristics, 10 percent or less will have strep throat.”-Hippocrates’ Shadow

throat cultures: “The problem with throat cultures is that they find too much strep. More than 10 percent of schoolchildren (the group at highest risk for strep throat infections), for instance, have live strep bacteria permanently and harmlessly in their throats, so even when there is no infection, a culture will be positive.”

But if we “use the test on a group of schoolchildren that has fewer than three of the four hallmark signs of strep throat. Only 10 percent or less will have a true case of strep throat, therefore no more than 10 percent of them can have positive test results that are right. But we also know that more than 10 percent of those being tested will have positive test results that are wrong (due to the harmless bacteria in their throat). Therefore, a positive test result in this group is mathematically guaranteed to be wrong more often than right. More positive results will be due to harmless bacteria than due to a strep infection. More positive results will be due to harmless bacteria than due to a strep infection.due to harmless bacteria than due to a strep infection. This situation, in which a positive test is more likely to be wrong than right, is very undesirable. We perform the throat culture test because we would like to accurately select the patients who should have antibiotics. But when we test people who have a less than 10 percent chance of strep throat, most of the people who are given antibiotics will be taking an unnecessary drug with potentially serious side effects. Unfortunately, the great majority of patients (schoolchildren and otherwise) that have a throat culture have fewer than three of the hallmark signs of strep throat, and often two, one, or even zero. Therefore most people who are given antibiotics because of a positive culture for strep throat don’t have strep throat.”-Hippocrates’ Shadow

Treatment: Antibiotics appear to do more harm than good? “In a brilliant sequence of six studies, the physicians used placebos and other modern scientific research techniques to examine the impact of antibiotics on the strep throat infection itself, and also on the rate of rheumatic fever that followed it. They published their landmark results for the first time in 1950, and established definitively that treating strep infections with antibiotics had reduced the chances of developing rheumatic fever. While the antibiotics had little impact on the strep throat itself’which seemed to last equally as long and cause symptoms equally severe’rheumatic fever occurred roughly 1 percent of the time after antibiotics were used. In those patients given placebos, it occurred roughly 2 percent of the time. Using antibiotics had cut the rate of rheumatic fever occurrence in half.”-Hippocrates’ Shadow

This is AMAZING to me. We are trained to treat ALL strep throats with antibiotics. But the reason we have been taught to treat with antibiotics (to prevent rheumatic fever) is rare and the antibiotics only reduce the risk of this complication by 1%!!! In fact “today we would likely have to treat more than a million in order to prevent a case of rheumatic fever. This changes things. The basis of treatment for any condition is the presumption that the disease poses more danger than the treatment. But 1 million prescriptions for antibiotics (to prevent one case of rheumatic fever) will cause more than twenty-four hundred potentially fatal allergic reactions…, as well as a hundred thousand cases of diarrhea and a hundred thousand rashes. In addition, long-term rheumatic heart disease is the target that antibiotics aim to prevent, but only a third of rheumatic fever cases result in heart disease. Therefore, the number of antibiotic prescriptions it takes to prevent one heart problem is three times as high as the number it takes to prevent rheumatic fever. To prevent one long-term heart problem it would take 3 million antibiotic prescriptions, and more than seven thousand [life threatening reactions].”-Hippocrates’ Shadow