The Bowdoin Orient

March 9, 2001
Volume CXXXII, Number 19

Ask Dr. Jeff

by JEFF BENSON, M.D. DUDLEY COE HEALTH CENTER JBENSON@BOWDOIN.EDU

Dear Dr. Jeff: My daughter was seen in the Health Center for a cough and a sore throat and was diagnosed with a "viral upper respiratory infection." Two days later, she went to the Emergency Room, was diagnosed with strep throat, and started on antibiotics. Why didn't you do a strep test at the Health Center and start the appropriate treatment then? She would have felt a lot better sooner. C.E.

   Dear C.E.: Proper clinical evaluation and treatment of a sore throat may be a little more complicated than you suggest. Many things can cause a sore throat, including viral or bacterial infections and post-nasal drip from sinus drainage or allergies.
   Infections with Group A Streptococci (the bacteria that cause "strep throat") are believed responsible for as few as five percent of sore throats.
   Strep throats typically begin with a significant fever and without a cough or other cold symptoms. A physical exam almost always shows a deeply reddened throat, with pus on enlarged tonsils, and swollen and tender neck glands.
   The two most common lab tests for strep throat are the rapid strep test (performed in the office with results in five minutes) and the throat culture (sent out to a hospital lab with results in two to three days). Neither, however, is entirely reliable.
   There are significant numbers of false negative and false positive results using the rapid strep test, especially if performed at the first onset of symptoms. This test measures your immunologic response to the presence of the strep bacteria. It is estimated that only 50 percent of those with positive throat cultures demonstrate this response to a degree measurable by a rapid strep test.
   The throat culture more accurately determines the presence or absence of streptococci themselves. However, the mere presence of the bacteria in someone's throat does not mean that they are responsible for that person's symptoms.
   He or she may be a chronic strep carrier and have a sore throat for other reasons. Chronic strep carriers always have strep growing in their throats and always culture positive for strep-whether or not their throats are even sore and even after antibiotic treatment! The strep carrier rate in healthy people approaches 20 percent.
   So how can a diagnosis of strep throat be made accurately? Through a process of clinical evaluation and judgment that balances out a patient's medical history, signs and symptoms, physical exam, and laboratory test results. There is rarely anything black-and-white about this process.
   Not every patient with a sore throat should have a strep test or throat culture. This judgment should follow largely from the prior evaluations. All tests, of course, have some inherent degree of inaccuracy. They are most likely to be helpful in a setting when they are more likely to be positive.
   Antibiotic treatment for proven strep throats is fortunately simple and definitely useful, although not for alleviating symptoms. The purpose of treatment is to prevent rheumatic fever and other possible (though uncommon) complications of streptococcal infection. Initiation of treatment can be safely delayed for up to two weeks from the onset of illness and may even be more effective if so delayed.
   Unnecessary antibiotic treatment, as we all know, should be avoided. Antibiotics can cause allergic reactions, side effects, and perhaps most importantly, the emergence of resistant organisms.
   One last point: at the end of all Health Center visits, we all explain that illnesses evolve, that what we evaluate today might look different tomorrow, that if things take a turn for the worse (or don't improve within the expected time), then to please come back for another visit. Our "same day appointments" and staff continuity make it very easy to check and re-check again. That's an important component of high quality care.
   Jeff Benson, M.D.
   Dudley Coe Health Center

Please address any questions or comments you may have related to medical care, public health, preventive medicine, health policy, health center services, or any other issue involving health or wellness, to jbenson@bowdoin.edu - and see your answer appear here in the Features section!