By Claire McCarthy at Boston Children’s Hospital

On the Richter Scale of childhood illness, strep throat ranks pretty low, but its little tremors can wreak a fair bit of havoc on the day-to-day lives of parents and children. It’s also one of those illnesses that’s so common that people often think they know everything there is to know about it. But as a pediatrician I’ve discovered that parents really don’t know everything about this pesky and painful illness.

Here are five important things you might not know about strep–but should:

1.  Not all sore throats are strep. In fact, at most 30 percent of sore throats are caused by group A streptococcus, the bacteria that causes strep throat. The vast majority of sore throats are caused by viruses. And while you may think you know it’s strep from how it looks or your past experience, studies have shown that it simply isn’t as easy as it might seem; viruses and strep can look remarkably similar. To make the diagnosis, we need to do a rapid strep test or a throat culture. So if your pediatrician insists on seeing your child instead of calling in a prescription, they are doing the right thing.

2.  Not all strep throats are sore. Kids with strep throat can have headaches, stomachaches, vomiting and rash, or some combination of these symptoms—and sometimes these symptoms can bother them more than their throat does. I’ve seen lot of kids in the office with vomiting or headache and no sore throat who turned out to have strep, much to the surprise of their parents.

3.  Strep usually gets better without antibiotics, but we treat it anyway. This one often surprises people. Our immune system is actually pretty good at fighting group A streptococcus, and will generally get rid of it in a few days. But we give antibiotics, for three reasons:

  • To make kids feel better faster. If you’ve ever had strep, you know how miserable it can feel.
  • To prevent complications. Although it’s rare, strep throat can lead to problems in the heart, kidney and even the brain. By treating the infection, we make those complications far less likely.
  • To prevent spread of the infection. Strep is very contagious, as many parents and teachers will tell you. Once someone has been treated with antibiotics for 24 hours, the chances that they will give it to someone else go way down.

4.  Having a positive culture doesn’t necessarily mean you have an infection. Strep can live in our noses, mouths and throats and not make us sick. This is called being a carrier, and it’s more common than people realize. Sometimes it’s hard to tell whether someone actually has strep throat or whether they are sick with a virus and happen to be a carrier! Because of this, we don’t recommend doing another test after treatment unless the person is still feeling sick. Most of the time being a carrier doesn’t cause trouble. If it seems to be causing recurrent infections, stronger antibiotics can be used, and sometimes a tonsillectomy is recommended.

5.  Even though you may feel better after a day or two, it’s important to take the full course of antibiotics. It really can be tempting to stop once that fever is gone and your child is happy and eating again—after all, they look completely better, and most kids don’t like taking medicine—but if you do, there’s a good chance the infection won’t really be gone and in a few days you’ll be right back where you started.