Sore Throats Mostly Viral, Not Strep

Yael Waknine

September 17, 2012

September 17, 2012 — The majority of throat infections are viral and should not be treated with antibiotics, according to new guidelines from the Infectious Diseases Society of America.

The recommendations, published online September 9 in Clinical Infectious Diseases, are aimed at limiting the antimicrobial treatment of viral infections and correctly identifying and treating cases of group A streptococcal pharyngitis ("strep throat"). Penicillin and amoxicillin are the drugs of choice for treating streptococcal infections, according to the recommendations.

Up to 70% of Americans with a sore throat receive antibiotics, according to a society news release. However, bacteria are responsible for only 20% to 30% of pediatric cases and 5% to 15% of adult cases.

"These important, timely guidelines provide guidance to physicians on when to test for, and how to treat, strep throat," Jesse T. Jacob, MD, assistant professor of medicine in the Division of Infectious Diseases at Emory University School of Medicine in Atlanta, Georgia, told Medscape Medical News. "Strep throat is a common disease, but viral infections are more common. It is important to differentiate them, so that patients do not get unnecessary antibiotics, which can carry side effects for the individual, and also increases the chance that the next infection (whether in the same person or the next) will become resistant to the antibiotic. It may also help kids avoid unnecessary surgery for recurrent sore throats." Dr. Jacob was not involved in writing the new guidelines.

Some Symptoms Overlap

Although bacterial and viral throat infections often have overlapping symptoms, other symptoms, such as cough, rhinorrhea, hoarseness, and oral ulcers, strongly suggest a viral infection, the authors write.

In contrast, a sore throat is more likely to be caused by group A strep if the onset of pain is sudden, swallowing hurts, and a fever is present. Such cases can be evaluated using a stand-alone rapid antigen detection test. Because children younger than 3 years are unlikely to have strep throat, testing is unnecessary, with the exception of certain circumstances such as an infected older sibling.

Throat cultures should only be used to confirm negative antigen tests in children and adolescents. They should be eschewed in adults because of their low risk for strep throat and even lower risk for complications such as rheumatic fever.

Once strep throat is confirmed, the treatment of choice remains a 10-day course of penicillin (or its congener amoxicillin), which has a narrow spectrum of activity, is cheaply available, and carries a low risk for adverse events.

"We recommend penicillin or amoxicillin for treating strep because they are very effective and safe in those without penicillin allergy, and there is increasing resistance of strep to the broader-spectrum — and more expensive — macrolides, including azithromycin," said lead author Stanford T. Shulman, MD, from the Ann & Robert H. Lurie Children's Hospital of Chicago and Northwestern University Feinberg School of Medicine, in the news release.

The guidelines also recommend against tonsillectomy for children with repeated throat infection, except in very specific cases (eg, children with obstructive breathing), because the risks of surgery are generally not worth the transient benefit.

The 13 recommendations replace those issued in 2002 and are presented in a novel format designed to facilitate use.

"The Q&A format of the guideline parallels in large part how a clinician would think through a patient with suspected strep throat. They are written precisely to help clinicians work through this tough but common issue," Dr. Jacob said, noting that patients will need to be taught that not all infections are bacterial, that antibiotics do not treat viral infections, and that antibiotics, as an unintended consequence, can be harmful.

"Antibiotics will not help a viral infection, but there are other treatments for sore throats, regardless of need for antibiotics. Clinicians will need to work with patients to communicate all the information, reassure them, and provide them with appropriate care," Dr. Jacob concluded.

The study was funded by the Infectious Diseases Society of America. Dr. Shulman reports having served as a consultant to Novartis Vaccines and Merck Vaccines and received research support from Quidel. One of the other authors has served as a consultant for SPD Development, Cornerstone BioPharma, and Rib-X Pharmaceuticals. Dr. Jacob has disclosed no relevant financial relationships.

Clin Infect Dis. Published online September 9, 2012. Full text