First, a disclaimer – I am biased. I have spent 30 years thinking, researching and writing about adult pharyngitis. My success in that field has stunned me. Of course I will overemphasize all arguments in favor of my opinion and poo-poo those in opposition.
The advocates of the rapid strep test make these assumptions:
- We should treat group A strep pharyngitis with antibiotics (preferably a penicillin or a cephalosporin).
- No other cause of pharyngitis deserves antibiotics.
- We should avoid antibiotics in all other pharyngitis as that increases the probability of antibiotic resistance.
They implicitly seem to assume that pre-adolescent pharyngitis studies apply to adolescents and young adults (older adults get pharyngitis much less commonly).
They also generally believe the manufacturers claim that the sensitivity of the rapid strep test is > 90%.
We recently laid out the case for other bacterial causes in adolescents and young adults.1 In that article, we present the evidence that both group C streptococcal pharyngitis and Fusobacterium necrophorum pharyngitis were relatively frequent and worth treating in adolescents and young adults. These infections rarely occur in pre-adolescents!
Experts generally assume that the rapid test has a sensitivity of greater than 90%. They believe this because most papers in the literature result from industry sponsored studies in which the staff members are carefully trained. Two recent studies challenge that belief2,3. In the first study, one in a family medicine training program, they observed a sensitivity of only 75%. That study also confirmed the importance of non-group A streptococcal pharyngitis. The second paper from Turkey found a sensitivity of only 65%.
The assumptions for recommending the rapid test only strategy are suspect in my mind. But then I am biased. But I have shared some data to support my opinion.
REFERENCES
1. Mitchell MS, Sorrentino A, Centor RM. Adolescent pharyngitis: a review of bacterial causes. Clinical Pediatrics 2011;50(12):1091–1095.
2. Tiemstra J, Miranda RLF. Role of non-group a streptococci in acute pharyngitis. Journal of the American Board of Family Medicine : JABFM 2009;22(6):663–669.
3. Gurol Y, Akan H, Izbirak G, et al. The sensitivity and the specifity of rapid antigen test in streptococcal upper respiratory tract infections. International Journal of Pediatric Otorhinolaryngology 2010;74(6):591–593.
{ 4 comments… read them below or add one }
our medical group now offers pharmacy strep tests for sore throats.
Because you don't need any more assessment than a rapid strep test for something a simple as a sore throat, apparently.
So your answer is?
Here's what I do. Take a history. Look at the patient.
If they're 13-35 with predominantly sore throat of 0-4 days duration, have fever, no cough, and positive anterior cervical LAD and they look uncomfortable but not 'really sick' then it is strep. Give them PCN(assuming no allergy)
If they have 2-3 of those things(and still are not 'really sick') then do the rapid strep and treat if positve with PCN and symptomatically if not.
If they have 0-1 of those things and are not 'really sick' then treat them symptomatically.
If they look really sick, or have had symptoms for more than 3-5 days or are worsening/not getting better after that time frame, then consider other etiologies beyond GAS and viral pharyngitis.
Seem fairly straightforward to me. But it is more than 'sore throat, do rapid strep test' caveman approach.
And in my residency in the mid 2000s we did strep cultures on our negative rapid streps and they were extremely accurate. In 3 years I doubt I had more than 2 or 3 positive cultures after a negative strep and and I strongly wager one of those was just a carrier.
Most of the positive cultures I get back are Strep C in those adolescents. Other than that, I basically agree with DB and JustaDoc.
My 10 year old son has tourettes syndrome. His tics had been mild until a few days ago. Another TS parent suggested giving my son the Rapid Strep test. Thing is though, he doesn't have a sore throat. Does that make sense. I do seem to recall that you can have the strep infection without the sore throat. Is that right?