Tuesday, September 18, 2012

New Guidelines for Treatment of Strep Throat

New guidelines for assessment and treatment of Strep throat were published in the Oxford Journals of Clinical Infectious Diseases this month.  They attempt to decrease the overuse of antibiotics to treat sore throats caused by a virus, since antibiotics are ineffective against viral illnesses. Streptococcus (AKA Strep) is a bacteria, and antibiotics do treat infections with Strep. (See Clinical Practice Guideline for the Diagnosis and Management of Group A Streptococcal Pharyngitis: 2012 Update by the Infectious Diseases Society of America for the full report.)

While these guidelines are written for physicians and other medical providers, if patients understand the guidelines it can help them know what to do when they (or their children) have a sore throat.  Many parents presume Strep with every sore throat, but in reality only 20-30% of sore throats are bacterial in kids.  The large majority (70-80%) are from a virus and do not need an antibiotic. In adults the number of sore throats needing antibiotics is even lower - only 5-15%.  Nationwide, 70% of people who go to a medical provider with a sore throat get an antibiotic. This means many are treated unnecessarily.

Why do we treat Strep throat with antibiotics? In most cases Strep throat will be handled by the body's immune system over a relatively short time.  Without treatment most symptoms go away within a few days. Before antibiotics were available most people with Strep throat got better on their own. Unfortunately the Strep bacteria can affect the heart (rheumatic fever) or kidneys (streptococcal glomerulonephritis) or cause other problems if left untreated. Treating with antibiotics early can prevent some of these complications. Treating also decreases the time that a person with Strep throat is contagious, so helps stop the spread of illness to friends and family members.

Why do we want to avoid antibiotics if it is a virus? Antibiotics do not help the body get better or even feel better faster if a virus is causing the symptoms. They simply are ineffective against viruses. They do carry risks: diarrhea and allergic reactions are two relatively common issues. Overusing antibiotics leads to bacterial resistance, which means when someone is sick with a bacterial infection, several antibiotics might fail because the bacteria has become a "super bug" and less inappropriate use will cause fewer super bugs.

How can you know when to bring your kids in for evaluation? Strep throat and viral sore throats have a lot of common symptoms. Strep throat typically causes a sudden onset of one or more of the following: sore throat, fever, rash, headache, abdominal pain, nausea, vomiting, or swollen glands.  If there are "cold" symptoms such as runny nose, cough, hoarse voice, diarrhea, or eye discharge, it is more often from a viral upper respiratory tract infection, not a bacterial infection.  Children under 3 years of age are less likely to get Strep throat, but it is very common in school aged children.  The only way to know if it is Strep throat or not is to get a throat swab and test it.  A rapid antigen test is typically available in less than 10 minutes. If it is positive, treatment is indicated. If it is negative, a culture can be done to confirm Strep or no Strep.  This takes about 2 days. To prevent rheumatic fever, treatment should be started within 9 days of symptoms starting. Unfortunately treatment does not affect the kidney disease that rarely is a complication of Strep throat.  It is not an emergency to run in to the ER overnight for possible Strep throat, but do bring kids in if they have symptoms of Strep without viral symptoms. Also bring them in if their viral symptoms warrant evaluation in their own right (difficulty breathing, extreme pain, dehydration) or if you are unsure what is going on.

My summary of the guidelines:

1. Establish the diagnosis by swabbing the throat and doing a rapid antigen test and/or culture.  Do not treat "because it looks like Strep" because it usually isn't.
2. If the rapid antigen test is negative in children and adolescents, a back up culture is indicated. Adults do not need a back up culture unless Strep is highly suspected.
3. Blood titers are not recommended to check for current Strep throat infection because they reflect past infections. These are used to evaluate more chronic conditions.
4. Testing is not recommended if symptoms suggest a viral infection (cough, runny nose, hoarseness, oral ulcers). Falsely positive Strep tests can happen, and then an unnecessary antibiotic would be given with a virus infection.
5. Children less than 3 years of age do not routinely need to be tested for Strep because they are very low risk of complications of rheumatic fever, but the provider can test them if they have known exposure and symptoms of Strep.
6. Follow up throat cultures after treatment are not routinely recommended but can be considered in certain circumstances (if carrier status is suspected).
7. Testing or treatment of contacts of patients with Strep throat is not recommended if those contacts have no symptoms. (This means if Brother has a positive Strep test, there is no need to test or treat Sister if she has no symptoms. But... if she develops symptoms she should come in for a test.)
8. Patients with Strep throat should be treated with an appropriate antibiotic for an appropriate time. This is typically a penicillin (such as amoxicillin) for 10 days. For those with a penicillin allergy, cephalosporins or clindamycin or clarithromycin for 10 days is recommended. Azithromycin for 5 days at Strep dosing levels is acceptable for patients with allergies to other antibiotics.
9. Use of fever reducer/pain relievers, such as acetaminophen or ibuprofen, should be considered as needed. Aspirin should be avoided in children. Steroids are not recommended.
10. Patients with recurrent Strep throat at close intervals should be evaluated for chronic Strep throat carrier status with repeated viral infections.
11. Strep carriers do not require antibiotics because they are unlikely to spread Strep to close contacts and are not at risk of developing complications of Strep (rheumatic fever).
12. Tonsillectomy is not recommended to reduce the frequency of Strep throat.


2 comments:

  1. I have being researching about bacterial infections and reading your blog, I found your post very helpful. Amoxil can be used to treat infections caused by bacteria such as pneumonia, ear infection and bladder infection.

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    1. William: Yes, Amoxil (amoxicillin) is a great antibiotic for many infections. Unfortunately the dosing requirement has increased over the years (25mg/kg/day has increased to 90-100mg/kg/day) for some infections due to bacterial resistance. Fortunately Strep throat still responds well to amoxicillin. There are some interesting studies that the other "normal" bacteria in your throat can block and protect the strep against it though. Not the typical bacterial resistance, but when appropriate doses of amoxicillin don't work, it isn't that the Strep germs are resistant, it is that the germs have friends protecting them!

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