You may have read my recent post about ear infections and how they are over-diagnosed and over-treated. Guess what—ear infections are not alone. Strep throat is another common pediatric infection that is over-diagnosed and over-treated. In adult patients, it’s easy to make a case for not treating it at all. And although kids aren’t just little adults, and the evidence is a little less clear-cut, pediatricians may need to back off, too. I know you already don’t believe me (nor do some of my patients…or my mother), but let me make my case:
Group A Streptococcal pharyngitis (which will henceforth be referred to as “strep throat”) is a sore throat caused by a type of bacteria called Streptococcus pyogenes. The same organism causes other infections as well, but I’ll focus on the throat. Common symptoms seen with strep throat include sore throat, fever, headache, and nausea. This disease is more common in school-age children and teenagers than it is in adults, but rarely seen in kids under 3. It’s one of the most commonly treated conditions in a pediatric office. In children, about 25% of sore throats are caused by strep. There are a few other causes, but the vast majority of them are viral.
If your child is diagnosed with strep throat, he’ll probably be given antibiotics. But here’s the secret: the antibiotics aren’t really for his throat.
Surprised? I was, too, the first time I heard it. But the truth is, strep throat goes away all by itself. Antibiotics can reduce the duration of symptoms by about 16 hours, but really don’t help the throat much more than over-the-counter pain medicines. I know what you’re thinking: your child had strep throat, got antibiotics, and felt better the next day. But what would have happened if it hadn’t been treated? Well, it would have gotten better 3-4 days after it started. Most parents take their kids to the doctor a day or two after symptoms start; and by the time they make it to the pharmacy and give the medication, antibiotics just don’t make that much difference. If started earlier in the illness, they work better, but they may also keep your child from developing immunity to the infection and make her more likely to get strep throat again.
Strep throat can have some complications, though. It’s not just the sore throat we worry about. Rarely, kids can get peri-tonsillar abscesses in the back of their throats. These happen in about 0.03% of people each year, and can be pretty severe, often requiring surgery. It makes sense that treating strep throat with antibiotics would reduce the risk of these abscesses, but the evidence is not that convincing. Many of the infections are caused by other bacteria, and many of these cases begin as an abscess, without a preceding sore throat–which means we can’t prevent them.
But the real reason we treat strep throat is to prevent something called “rheumatic fever.” This is a problem that occurs when a someone’s body over-reacts to a strep infection and starts attacking itself. Rheumatic fever has a number of different symptoms, but the one we worry about most is damage to the valves in the heart. It’s hard to find statistics about rheumatic fever—because it almost never happens. It occurs in 15 per 100,000 hospitalized children in the US each year. It’s important to note that this number includes only hospitalized children, and that in a given year, most children are not hospitalized. In fact, 97% of children make it through the year without being hospitalized. This means that, in a given year, about 4.5 out of every million children gets rheumatic fever–or conversely, that of the 75 million children in the US, 74,999,662 of them will make it through the year without getting rheumatic fever. 40% of children with rheumatic fever don’t have any heart involvement. So the real number we’re talking about is about 200 out of 75,000,000 children each year. (This is admittedly rough math, but the best I can do with the statistics available for an incredibly rare disease.)
Some would argue that the reason for rheumatic fever’s decline is that we are so diligent at treating strep throat with antibiotics. The only way to know for sure would be to do a randomized controlled trial where patients with strep are assigned to “treatment” or “control” groups and then compare the results. The only studies that did this were prior to 1970, when a particularly nasty strain of strep was causing a lot of rheumatic fever. They were able to prevent just over half of these cases by treating strep throat with antibiotics. While there were a few other isolated outbreaks of rheumatic fever in the 1980’s, there hasn’t been a clinical trial in the past 45 years in which anyone (even patients treated with placebo) got rheumatic fever. That makes it hard to justify the claim that antibiotics are helpful. And when physicians in the UK decreased their antibiotic use for children with sore throats by 40%, there was no increase in either rheumatic fever or peri-tonsillar abscesses. In reality, the decreased rates of rheumatic fever probably have more to due with mutations in the strep bacteria and improved hygeine.
Think this is getting complicated? What if I told you that 10-15% of healthy children (without sore throats) are strep carriers? This means that the strep bacteria just hangs out in their throats without causing symptoms. It also means that any time a doctor swabs that child’s throat, the test will be positive—even in the 75% of sore throats that are caused by a virus. And I haven’t even brought up the fact that many children (and even more adults) are treated for strep without any test at all–or worse, with a negative test.
Antibiotics are not without harm. They cause anaphylactic (allergic) reactions, diarrhea, rashes, and other side effects far more frequently than they prevent rheumatic fever. When over-used, they lead to antibiotic-resistant bacteria that will cause far more deaths than rheumatic fever. If the economic cost of antibiotics and subsequent office or emergency room visits for their side effects is factored in (we’re talking hundreds of millions of dollars per year), the argument becomes even more convincing. While antibiotics may be justified in developing nations with the rates of rheumatic fever are higher, or during local outbreaks of rheumatic fever, I would argue that they are not worth the health risks or the economic cost for the typical case of strep throat.