Friday, February 10, 2012

Recurrent Strep Throat

Rapid Strep testing
Recurrent strep throat is a problem for many families.  Some kids seem to catch strep the minute it enters their classroom or neighborhood.  Their parents recognize the symptoms and bring the child in immediately for diagnosis and treatment so they can get the child back to school in 24 hours (and parents can get back to work).

The problem with this rapid treatment approach is it doesn't allow the child's immune system to rev up against Strep. The antibiotic kills it off, and doesn't leave "memory" of the Strep bacteria. If given a few days, the body's immune system builds fighter cells to kill off the Strep bacteria.  Some of these cells hang around as "memory" cells so that with the next exposure, they round up the troops and kill off the Strep before it becomes a big infection.

It's a matter of short term versus long term solutions.  The short term solution is to quickly treat so everyone can get back to their routine lives, but leaves opportunity for recurrence. The long term solution is to treat symptoms to maintain hydration and comfort for a couple of days and then to treat with antibiotic. This requires more time at home and delays return to school.  Which option is better for your child depends on your current needs and long term goals.

Parents chime in: Knowing the short term/long term issues with rapid treatment of Strep throat, will you take your kid to their doctor or walk in clinic at the first sign of sore throat or wait?


  1. Good Evening Dr. Stuppy,

    This is a very interesting post. As a pediatric infectious diseases physician I have had the chance of treating and consulting in the outpatient clinic on many cases of recurrent tonsillitis. I'm not aware of delaying treatment being a solution to preventing recurrent tonsillitis. Do you have a reference that demonstrates this?

    I think the immunology that you discuss likely does not work for group A strep. In fact, there are over 100 different Group A streptococcus serotypes based on the M protein of this bacteria. I know there has been attempts to develop a vaccine with the attempt to create antibodies and possibly memory T cells that would help prevent group A streptococcus infections, however these vaccines have yet to be successful. I speculate this is likely due to the large number of serotypes with the potential of causing an infection.

    I think one of the most important points regarding group A streptococcus pharyngitis, aka Strep Throat, is to use the test when it should be used. Many times rapid group A streptococcus cultures will be done when pharyngitis is not present and a stomach ache is without fever. This is not Strep throat or Strep pharyngitis as there is no pharyngitis. Group A streptococcus can live happily in the back of someone's throat without causing infections. The classic signs and symptoms of Strep throat are fever > 100.4, tender anterior cervical node, tonsillar swelling or exudate, and absence of respiratory symptoms such as cough. Additionally, group A strep pharyngitis is unlikely to occur in children less than 3 years of age unless a family member has recently had the infection. Here is an interesting paper from JAMA looking at these symptoms with the modified Centor scoring system:

    Finally, the main reason to treat group A Streptococcus is to prevent the complications such as rheumatic fever and post-streptococcal kidney disease or arthritis. While treatment might decrease the duration of infection by a day it is the prevention of these complications that is important. In regards to the time period in which treatment needs to be initiated to prevent these complications, I am not aware of any data suggesting what that window exactly is.

    Thanks for the opportunity to comment on this blog. I look forward to further discussions involving such great infectious diseases topics.


    Jason Newland, MD
    Pediatric Infectious Diseases Physician
    Children's Mercy Hospitals & Clinics
    Kansas City, MO

  2. Dr Newland:

    Thank you for your educational comment. I have been talking about this concept since I learned it in my residency training and do not have any current research since it was so long ago. I fully believe in using evidence based medicine, but have never seen anything to contradict this previously. I do love medicine because we continually learn new things.

    I continue to think that parents don't need to run right in to a walk in clinic or ER to treat the sore throat, since delay of a day or two should not impact complication risks. If that were the case, I suspect we should be putting all children on antibiotics until the culture is negative. (Clarification to patients: this is NOT recommended in most cases!) I see the highest number of false negative rapid strep tests (negative in the office, positive culture) in the first 24 hours of illness. (This is from personal observation in my office over the years, but would love to see real data on this if anyone knows it.)

    The biggest reason for this blog was to reassure parents that it is okay (and in my opinion preferable) to wait to go to their medical home for evaluation and treatment. They often ask for antibiotics when the rapid test is negative, and I want them to be reassured that the culture is the "gold standard" and waiting to see if it is positive is not a bad thing. Historically this is the situation in which I most commonly use the argument that having the Strep for a couple days is a good thing and with a negative rapid test it is most likely that the child has a virus and antibiotics are not helpful for viral infections. I also use this information when parents are distressed at 11pm because their child has a sore throat and they feel guilty that they don't want to pay a higher co pay or wake all the kids for a trip to the ER/UC, but want to do what's best for their child. I want them to know that not only is it acceptable, but preferable to do symptomatic care overnight or while awaiting the culture results. I will change my tune with the information you provided unless I find more facts-- though I still support waiting for all the other reasons!

    What are the other reasons? I have seen many kids inappropriately treated for "Strep" with standard dosing of azithromycin (not 12mg/kg/day and no history of penicillin allergy). I have seen kids tested (and treated) for Strep who present with typical URI symptoms (increasing the likelihood of false positive testing as you alluded to above). I have even seen kids treated for sore throat without any testing because "it looks like Strep".

    The stimulus for this quick blog was to get parents thinking about how to best utilize healthcare. I still think going to the medical home is best since there are so many reasons for this, and unless there is difficulty breathing, dehydration, or other emergent needs, using the PCP office is preferable. I do appreciate your comments and will look into this further because I want to practice evidence based medicine, and unless past information is contradicted, I continue to use it. I wonder where my attendings learned this information... anyone out there have any references?