Blog | Friday, October 5, 2012

IDSA's strep pharyngitis guideline disappoints me


As soon as I read the title of the IDSA guidelines I understood. I understood that they were disease focused rather than symptom and diagnosis focused. Therein lies the problem.

Patients do not come to see use asking if they have strep pharyngitis. They come to us complaining of a sore throat plus other symptoms. They have symptom duration and severity.

I have written previously about the affect heuristic. That heuristic explains that our positive feeling about an issue changes how we estimate both risks and benefits. Thus I believe that the committee consisted primarily of strep experts. They like the idea of treating strep, but even more strongly dislike the idea of giving antibiotics to pharyngitis patients unless they are strongly convinced that group A strep caused the pharyngitis.

They have dichotomized the sore throat decision into group A strep or not. They systematically discount the importance of any other diagnosis. The committee uses the excuse that we do not have adequate evidence to make decisions about other bacteria, specifically group C streptococcal pharyngitis and Fusobacterium pharyngitis. They do a nice review of the appropriate literature, but then decide that without clear evidence of benefit we should avoid antibiotics and the risk of furthering antibiotic resistance.

But I believe they missed the problem that practicing physicians should understand. How should we think about patients presenting with sore throats? This guideline encourages the behavior that I see too often (and 1 comment already endorsed): have the nursing staff do a rapid test (regardless of symptoms) and give antibiotics for a positive rapid strep test.

This approach works reasonably well for at least 80% of patients. But we have a responsibility to know when our patient is not in the "short head" but rather in the "long tail". Last year I wrote this post, "How guidelines and performance measures can increase diagnostic errors!"

And this is the problem that I have with this guideline. Without intent, this guideline will encourage a reflexive approach to sore throats. This approach works most of the time. But we do not need physicians who act reflexively. We need physicians who have a broader problem representation of sore throat, and thus know when to think!

Judy Bowen wrote beautifully about problem representation in her 2006 NEJM article. This guideline encourages us to have a simple problem representation, a patient with a sore throat. I would encourage us to distinguish a pre-adolescent patient from an adolescent or young adult. I would encourage us to distinguish patients with a 1 or 2-day history of symptoms from those with longer symptoms. I would want physicians to actually examine patients, especially adolescents and young adults. Does the patient have posterior cervical adenopathy? (Should we consider infectious mononucleosis or acute HIV?) Has the patient had rigors or night sweats? Does the patient have worsening symptoms or unilateral neck swelling? (Peritonsillar abscess or Lemierre syndrome)

This is not a trivial point. This guideline, and other similar disease oriented guidelines, discourages clinical diagnostic reasoning. The guideline oversimplifies the clinical situation. It discourages a nuanced approach to these patients.

Usually that approach works, but ask anyone who has had Lemierre syndrome, or the parents of those who did not survive this rare horrible infection. I personally find the committee's dismissal of Fusobacterium pharyngitis disturbing. Here is their paragraph: "Several recent reports have documented the isolation of Fusobacterium necrophorum from throat swabs of adolescents and young adults with nonstreptococcal pharyngitis . Some studies also suggest a role for F. necrophorum in cases of recurrent or persistent pharyngitis (with or without bacteremia or Lemierre's syndrome). F. necrophorum is the causative agent of most cases of Lemierre's syndrome, which requires urgent antibiotic therapy, but at present, the evidence for F. necrophorum as a primary pathogen in acute pharyngitis in adolescents and young adults is only suggestive. Further study is required to determine the role of F. necrophorum in acute pharyngitis, as well as the necessity for and effectiveness of antibiotic therapy.

They do not discuss at all how to diagnose Lemierre syndrome! Nor do they really show proper respect to Group C pharyngitis, infectious mononucleosis or acute HIV. This guideline exemplifies the problem with too many guidelines in 2012. They answer a question that they find interesting, but ignore the question that family physicians, emergency physicians, internists and pediatricians need to ask.

And therefore this guideline disappoints me.

db is the nickname for Robert M. Centor, MD, FACP. db stands both for Dr. Bob and da boss. He is an academic general internist at the University of Alabama School of Medicine, and is the Associate Dean for the Huntsville Regional Medical Campus of UASOM. He also serves as a frequent ward attending at the Birmingham VA Hospital. This post originally appeared at his blog, db's Medical Rants.