Sore Throats- Is it Strep?

INTRODUCTION — A sore throat (pharyngitis) is a common problem, and usually is caused by a viral or bacterial infection. Sore throat usually resolves on its own without complications in adults, although it is important to know when to seek medical attention.
Viral pharyngitis can be caused by one of many viruses, many of which can also cause an upper respiratory infection such as the common cold. Viral pharyngitis is not treated with antibiotics, but instead may be treated with rest, pain medication, and other therapies aimed at relieving symptoms.
Strep throat is a particular kind of pharyngitis that is caused by a bacterium known as group A streptococcus (GAS). Strep throat is usually treated with a course of antibiotics.
A topic that discusses sore throat in children is available separately. (See “Patient information: Sore throat in children”).
SIGNS AND SYMPTOMS
Viral pharyngitis — The majority of cases of sore throat are caused by a virus. The most common include viruses that cause upper respiratory infections, such as the common cold. (See “Patient information: The common cold in adults”).
Symptoms that may occur with a viral infection can include a runny nose and congestion, irritation or redness of the eyes, cough, hoarseness, or soreness in the roof of the mouth. In addition, viral infections may cause a fever and cause the person to feel quite ill.
Strep throat — Approximately 10 percent of cases of sore throat in adults are caused by strep throat. Signs and symptoms of strep throat include the following (show figure 1):
• Significant soreness of the throat
• Fever (temperature greater than 100.4ºF or 38ºC)
• Enlargement of the lymph glands in the neck
• White patches of pus on the side or back of the throat
• Absence of cough, runny nose, or irritation/redness of the eyes
Other infections — Many other, less common but more serious infections can cause a sore throat, including mononucleosis (mono), influenza (the flu), N. gonococcus (gonorrhea), human immunodeficiency virus (HIV), and others. (See “Patient information: Symptoms of HIV infection” and see “Patient information: Gonorrhea” and see “Patient information: Influenza symptoms and treatment” and see “Infectious mononucleosis in adults and adolescents”).
Because it is not easy to determine the cause of strep throat based on symptoms, it is important to consult with a healthcare provider if one or more of the following is present:
• Exposure to someone with known strep throat or a sexually transmitted infection
• Fever (temperature ≥ 101ºF or 38.4ºC)
• Throat pain that is severe or does not begin to improve after 5 to 7 days
Signs of a more serious problem — People with one or more of the following should see a healthcare provider immediately because these may be signs of a more serious problem.
• Difficulty swallowing or breathing
• Skin rash
• Drooling
• Swelling of the neck or tongue
• Unable to drink or eat
• Voice sounds muffled
• Stiff neck or difficulty opening the mouth
DIAGNOSIS — Pharyngitis resolves without specific treatment in most cases. There is no specific treatment for viral pharyngitis, the most common cause of a sore throat. Symptoms of strep throat may respond a day or so earlier with antibiotic treatment, but will also resolve without treatment. The main reason to diagnose and treat strep is to prevent rheumatic fever, although this complication has nearly disappeared in industrialized countries.
Is it strep or not? — The most accurate way to determine if a person has strep throat is to use a combination of the person’s signs and symptoms (described above) and perform a rapid test or throat culture if there are two or more signs/symptoms of strep (see “Strep throat” above). People with fewer than two signs/symptoms usually do not need testing or treatment.
Rapid test — The rapid test determines if there are bacteria on a throat swab. The test can be done in a clinician’s office and the results are available within a few hours. The test is accurate in most cases, although a small percentage of tests are falsely negative (the bacteria are present but the test is negative).
Throat culture — A throat culture involves swabbing the throat, sending the swab to a laboratory, and waiting 24 to 48 hours for the results. Throat cultures are slightly more accurate than the rapid test.
TREATMENT
Sore throat treatment — Antibiotics do not improve throat pain caused by a virus and are not recommended. Sore throat caused by viral infections usually lasts four to five days. During this time, treatments to reduce pain may be helpful. Several therapies can help to relieve throat pain.
Pain medication — Throat pain can be treated with a mild pain reliever such as acetaminophen (Tylenol®) or a non-steroidal anti-inflammatory agent such as ibuprofen or naproxen (Motrin® or Aleve®).
Oral rinses — Salt-water gargles are an old stand-by for relief of throat pain. It is not clear that it is effective, but it is unlikely to be harmful. Most recipes suggest 1/4 to 1/2 teaspoon of salt per one cup (8 ounces) of warm water.
Sprays — Sprays containing topical anesthetics (eg, benzocaine, phenol) are available to treat sore throat. However, such sprays are no more effective than sucking on hard candy.
Lozenges — A variety of lozenges (cough drops) are available to treat throat pain or relieve dryness. However, it is not clear that lozenges work any better than other forms of hard candy, which are generally less expensive.
Other interventions — Other interventions include sipping warm beverages (eg, honey or lemon tea, chicken soup), cold beverages, or eating cold or frozen desserts (eg, ice cream, popsicles).
Alternative therapies — Health food stores, vitamin outlets, and Internet Web sites offer alternative treatments for relief of sore throat pain. We do not recommend these type of treatments due to the risks of contamination with pesticides/herbicides, inaccurate labeling and dosing information, and a lack of studies showing that these treatments are safe and effective.
Strep throat — Although strep throat typically resolves on its own within two to five days, treatment with antibiotics is recommended for adults whose rapid test or throat culture indicates the presence of GAS bacteria. Antibiotic treatment can:
• Reduce the severity and duration of symptoms slightly, usually by one day
• Reduce the small risk of complications
• Decrease the risk of spreading the infection to others
Antibiotics — Penicillin, or an antibiotic related to penicillin, is the treatment of choice for strep throat. It is usually given in pill or liquid form two to four times per day for 10 days. A one time injection of penicillin is also available. People who are allergic to penicillin are given an alternate antibiotic. It is important to finish the entire course of treatment to completely eliminate the infection.
Symptoms usually begin to improve within three to four days after starting the antibiotic. If symptoms do not begin to improve or worsen during this time, the person should see their healthcare provider to determine if further testing is needed.
Return to work/school — Anyone who has been diagnosed with strep throat should stay home from work or school until he/she has completed 24 hours of antibiotics. Within 24 hours of beginning antibiotic treatment, the person becomes significantly less contagious [4] .
Anyone who has a sore throat (not diagnosed as strep) may participate in usual activities as soon as he/she feels well.
PREVENTION — Hand washing is an essential and highly effective way to prevent the spread of infection. Hands should be wet with water and plain soap, and rubbed together for 15 to 30 seconds. Special attention should be paid to the fingernails, between the fingers, and the wrists. Hands should be rinsed thoroughly, and dried with a single use towel.
Alcohol-based hand rubs are a good alternative for disinfecting hands if a sink is not available. Hand rubs should be spread over the entire surface of hands, fingers, and wrists until dry, and may be used several times. These rubs can be used repeatedly without skin irritation or loss of effectiveness. Hand rubs are available as a liquid or wipe in small, portable sizes that are easy to carry in a pocket or handbag. When a sink is available, visibly soiled hands should be washed with soap and water.
Hands should be washed after coughing, blowing the nose, or sneezing. While it is not always possible to limit contact with a person who is sick, avoiding touching the eyes, nose, or mouth after direct contact can help to prevent the spread of infection.
In addition, tissues should be used to cover the mouth when sneezing or coughing. These used tissues should be disposed of promptly. Sneezing/coughing into the sleeve of one’s clothing (at the inner elbow) is another means of containing sprays of saliva and secretions and has the advantage of not contaminating the hands.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.uptodate.com/patients). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable.
• National Library of Medicine
(www.nlm.nih.gov/medlineplus/healthtopics.html)
• National Institute of Allergy and Infectious Diseases
(www.niaid.nih.gov/)
• Infectious Diseases Society of America
(www.idsociety.org)
• Centers for Disease Control and Prevention (CDC)
Phone: (404) 639-3534
Toll-free: (800) 311-3435
(www.cdc.gov)
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REFERENCES
1 Bisno, AL. Acute pharyngitis. N Engl J Med 2001; 344:205.
2 Bisno, AL, Gerber, MA, Gwaltney, JM, et al. Practice guidelines for the diagnosis and management of group A streptococcal pharyngitis. Clin Infect Dis 2002; 35:113.
3 Humair, JP, Revaz, SA, Bovier, P, Stalder, H. Management of acute pharyngitis in adults: reliability of rapid streptococcal tests and clinical findings. Arch Intern Med 2006; 166:640.
4 Snellman, LW, Stang, HJ, Stang, JM, et al. Duration of positive throat cultures for group A streptococci after initiation of antibiotic therapy. Pediatrics 1993; 91:1166.