Infectious Disease Society of America Updates Guidelines for Strep Throat

The Infectious Disease Society of America updated its 2002 guidelines for the diagnosis and treatment of Group A streptococcal sore throat.  In adults with a sore throat, only 5 – 15% actually have Group A streptococcal sore throat and require an antibiotic to treat the illness. Adults in that group usually have been in the proximity of young children or adolescents who have strep throat.  In 85 – 95% of the cases, the adults have a viral illness that is causing their sore throat and viruses do not respond to the use of antibiotics.    For patients at risk for Group A streptococcal sore throat, usually presenting with fever, swollen neck lymph glands and an exudative pharyngitis; it is recommended that a rapid antigen detection test be performed to confirm the diagnosis and appropriately start the patient on antibiotics.

According to Stanford Shulman, MD of Northwestern University’s Feinberg School of Medicine in Chicago, once the rapid antigen detection test is positive no confirmatory formal throat culture is necessary.  If the test is negative in a child or adolescent only, they recommend performing a formal throat culture to rule out the bacterial infection. This is not necessary for adults because there is a low risk of them having this type of infection and very low risk of complications like rheumatic fever.

Once strep throat is diagnosed, the treatment of choice remains penicillin or amoxicillin taken for 10 full days. If the patient is penicillin allergic, alternative choices of antibiotics including cephalosporins, clindamycin or clarithromycin are warranted.  Acetaminophen and non steroidal anti-inflammatory medications are acceptable to reduce discomfort and symptoms.

Distinguishing between a viral sore throat and bacterial Group A streptococcal sore throat is very difficult using symptoms alone since the bacteria have changed their presentation as an adaptive survival mechanism. Most clinicians however feel confident that if the patient has a runny nose (rhinorrhea), hoarseness, mouth ulcers and cough it is probably viral and does not require antibiotics.

This guideline change comes on the heels of a report in the Archives of Internal Medicine pointing out that antibiotic use by senior citizens in the southern United States is more frequent in January through March than in other parts of the country. The study talks about the inappropriate use of oral antibiotics during the cold and flu season leading to bacteria becoming resistant to simple and inexpensive antibiotics.  In addition to a resistance to antibiotics, we are observing an increased number of complications of antibiotic use such as antibiotic related colitis (clostridium difficile).

This information is presented as an educational effort especially for patients who demand an antibiotic inappropriately when they catch a cold (viral illness) or who demand an antibiotic when they travel “just in case I catch a cold”.