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GAS: The Stray Dog of Bacterias – An Addendum

January 2, 2013

Well consider me embarrassed!

Last week I made a post on GAS. As with most of my posts, it was intended to be an overview of a common topic discussing primarily discussing its pathophysiology. However, I definitely should have taken a little more time to delve into the efficacy and necessity of treatment with antibiotics.

A huge thank you to Dr. Lars Peterson (@LarsKristofer), an EM resident from Rochester, NY, who helpfully pointed out this glaring omission with a comment linking to a post by Dr. David Newman, the genius of SMARTEM fame, that outlined the historical background for the use of antibiotics for GAS pharyngitis and concluded that its treatment may do more harm than good. He also has an amazing podcast here. This is at odds with the practice pattern of every physician that I have worked with and the practice guidelines from the Centers for Disease Control, the Infectious Disease Society of America (2012)American Heart Association (2009) and, closer to my home, the Alberta Medical Association.

But that doesn’t mean he’s wrong. Please read his very good review here and podcast here. There is also a 2006 Cochrane review on this very topic that I did not include in my previous post. Its conclusions were much less fierce.

-The evidence for antibiotics preventing post-strep gromerulonephritis is almost non-existent. Truly, no conclusions could be drawn as it was so rare with only 2 cases reported in 10 studies that reported this end-point.

-While the RR of rheumatic fever was decreased by treatment with antibiotics, Dr. Newman pointed out that the lack of rheumatogenic strains found in the modern Western world make the NNT to prevent this end point would be extraordinarily high (estimated at an NNT of 40,000). A 16 hour decrease in symptom duration was also found, but other treatments (Acetaminophen and NSAIDS in this review and corticosteroids in this one) are also effective for symptomatic treatment.

-The Cochrane review concluded that antibiotics did reduce the risk of otitis media, sinusitis and peritonsillar abscess, however, the NNT was high (46 for peritonsillar abscess). However, Dr. Newman’s podcast noted that sinusitis and otitis media were noted more often in earlier studies but did not seem to be affected, retropharyngeal abscess were too extraordinarily rare to be studied for prevention with antibiotics and, while peritonsillar abscess was affected the affect was slight (ARR of 0.8% for an NNT of 125).

-Antibiotics also have complications like anaphylaxis, diarrhea, yeast infections and rash.

All of this being said, is anyone regularly seeing high risk and/or culture-confirmed GAS pharyngitis and not prescribing antibiotics? I still find significant resistance to my “no antibiotics are needed” speech from patients who are at a low risk for having bacterial pharyngitis and want an antibiotic to “fix them,” especially when they “always get antibiotics” for this from the “other doctors” who must be a lot wiser than me. I don’t know if I could pull off “it is a bacteria, but you still don’t need antibiotics” and, while the complications are not common, I feel that I would have difficulty defending myself if my patient developed something I might have prevented had I not ignored generally accepted practice guidelines.

Thanks again to Dr. Peterson for the comment. I am smarter for it and, while I think I’m going to stick with my antibiotics for GAS pharyngitis for the time being (maybe I’m a wimp?), I certainly have a better understanding of the slightness of their benefits and may reassess my position as I get older and wiser.

In the future I will be making more of an effort to post on smaller subjects to allow for a more critical appraisal of the literature. I definitely bit off more than I could chew trying to review all of the non-suppurative GAS pharyngitis complications in a single post and completely dodged an important discussion.

Brent Thoma @boringem


From → Medical

  1. Thanks for the hat tip. 🙂

    I think this is one of the areas where our practice, the EM boards, patient expectations, other society guidelines, etc. make it really hard to change our practice patterns. Maybe when I’m an attending I’ll venture into this brave new world, but for now in the comfort of residency I’m prescribing the antibiotics.

    Its interesting reading the AHA guidelines – and their statements of level of evidence. They move from diagnosis/when to test/etc. to what to treat with (in the primary prevention section). The problem is that the level of evidence of IF treatment should happen seems low.

    Oh, well. Love the blog, can’t wait until the next post.


    • Great summary of the issue. That’s where I ended up as well.
      Thanks for reading and keeping me honest!

  2. Thanks for this post. Interesting food for thought and very topically relevant to my current practice. Will certainly raise this one at some point during either resident rounds or our EBM rounds to see what sort of discussion it provokes.

  3. Chris Krause permalink

    Excellent summary of the literature on treatment!

    The reasons listed above are why I NEVER treat pharyngitis on spec, ever. I didn’t as a family doc, and now as an ER resident I only would if my preceptor insisted. I tell parents that almost everyone gets better from this, that the treatment is intended to decrease future complications, which are extremely rare in our part of the world (I have seen estimates as high as NNT of 5,000,000 to prevent one case of valvular heart disease), and that the abx will do their job for this purpose as long as they are started within 9 days of illness onset. Since the symptom benefit is minimal, and there are risks to treatment, it can only do harm to treat on spec.

    If I have a positive swab then I treat, because like you, I feel at the moment there is not yet enough support for symptom-only treatment, though I usually tell parents “there is some debate about whether this is necessary, at the moment we still do it but we may learn in the future that it doesn’t really matter”. I always use penicillin. I don’t give a crap if amoxil tastes better, that’s mom’s problem, why use broader spectrum when narrow works the same or better? I always treat for 10 days. I list risks of abx as: allergic rxn, thrush/yeast, and antibiotic associated diarrhea, and I quote a NNTH of 17, which I got from a review article in the journal Canadian Family Physician.

    Parents very rarely argue after I give them my spiel explaining my rationale, because I have practiced it hundreds of times and I think I have worked most of the kinks out. If they still don’t believe me, which does still happen sometimes, mostly when there is a language barrier or if the parents are very sketpical/suspicious of mainstream medicine (then why do you want abx in the first place?), I just say “I’m not trying to make your life difficult, my job is to assess you and then make a recommendation, and this is my recommendation. It’s how I would treat my own family member. if you want to get a 2nd opinion from another MD then feel free to do so.”

    Finally I think we should all remember the fact that under 5 years of age children will NOT get a typical strep pharyngitis presentation, they are more likely to get cough, runny nose, generic URTI symptoms, and we never swab those kids either, and yet somehow they survive.
    I found this last fact hard to believe when I first read it, however I have since seen a few dozen cases like which swabbed positive for strep (most of those kids I swabbed at mom’s request after an older sibling was diagnosed). So how many of those kids are getting missed, with few apparent clinical consequences?

    Just a few thoughts.

    • Wow.
      Krause, those were quite the thoughts.
      The way you bust this stuff out off the top of your head amazes me. We don’t seem to teach as much about this kind of thing as you do in FM – not enough time with all the sepsis/ACS/trauma!
      Any chance you’d ever consider putting together a/some post(s) on your on or on here? I’d love to read them!

      • Chris Krause permalink

        That’s really kind of you to say.. I would love to join the blogosphere (do people still say blogosphere?) because as you know there are definitely some topics that I can get really riled up about.. but the skill you bloggers have, that I lack, is being able to actually keep it up over time., my desire to rant seems to come up randomly, usually when I’m supposed to be working on something else. But now that FOAM(ed) seems to be gaining so much momentum maybe I’ll have to think harder about it.

      • Well if there’s anything you’d like to put together an eloquent rant about, I’d be happy to host a “guest post.”

        Electricity and toxic mushrooms are areas of rare expertise.. Let me know if you’d be up for it!

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