Home > Health Library > Strep Throat
Strep throat is a
bacterial infection in the throat and the
tonsils. The throat gets irritated and
inflamed, causing a sudden, severe sore throat.
Strep throat is caused
by streptococcal (strep) bacteria. There are many different types of strep
bacteria. Some cause more serious illness than others.
some people are quick to think that any painful sore throat is strep, sore
throats are usually caused by a
viral infection and not strep bacteria. A sore throat
caused by a virus can be just as painful as strep throat. But if you have cold
symptoms such as coughing, sneezing, or a runny or stuffy nose, you probably do
not have strep throat.
The most common symptoms of
strep throat are:
You may also have a headache and belly pain. Less common
symptoms are a
red skin rash, vomiting, not feeling hungry, and body
Strep throat can be passed from person to person. When a
person who has strep throat breathes, coughs, or sneezes, tiny droplets with
the strep bacteria go into the air. These droplets can be breathed in by other
people. If you come into contact with strep, it will take 2 to 5 days before
you start to have symptoms.
Your doctor will do
a physical exam, ask you about your symptoms and past health, and do a
lab test such as a throat culture or rapid strep test.
A rapid test gives a result within about 10 minutes. But sometimes the test doesn't show strep even when it is present. A culture takes one or two days but is better at finding all cases of strep.
If the rapid strep test is positive and says that you do have
strep, there's no need to do the throat culture.
Doctors usually treat strep throat with
antibiotics. Antibiotics shorten
the time you are able to spread the disease to others (are contagious) and
lower the risk of spreading the infection to other parts of your body. Antibiotics also may help you feel better faster.
You are contagious while you still have symptoms. Most people stop being
contagious 24 hours after they start antibiotics. If you don't take
antibiotics, you may be contagious for 2 to 3 weeks, even if your symptoms go
Your doctor may also advise you to take an over-the-counter
medicine like acetaminophen (such as Tylenol) or ibuprofen (such as Advil or
Motrin) to help with pain and lower your fever. Be safe with medicines. Read and follow all instructions on the label. Do not give aspirin to anyone
younger than 20. It has been linked to Reye syndrome, a serious illness.
To avoid getting
strep throat, it is a good idea to avoid contact with anyone who has a strep
infection. If you are around someone who has strep, wash your hands often.
Don't drink from the same glass or use the same eating utensils. And don't
Bacteria can live for a short time on
doorknobs, water faucets, and other objects. It's a good idea to wash your
If you have a strep infection, there are things
you can do to avoid spreading it to others. Use tissues you can throw away
instead of handkerchiefs, wash your hands often, and do not sneeze or cough on
others. Antibiotics can shorten the time that you are contagious. It is a good
idea to stay home from work or school until 24 hours after you have started
Learning about strep throat:
Living with strep throat:
Health Tools help you make wise health decisions or take action to improve your health.
Strep throat is
caused by streptococcal (strep) bacteria, most often by group A beta-hemolytic
streptococcus (GABS). Other types of strep that can sometimes infect the throat
are groups C and G strep bacteria.
A strep infection causes the
throat (pharynx) and the
tonsils or adenoids to become irritated,
inflamed, and painful.
Sore throats are
most commonly caused by
viral infections or other irritants such as smoke,
allergies, dry air, or a throat injury, and not by a strep infection.
Strep throat can
be passed from person to person. When a person infected with strep throat
breathes, coughs, or sneezes, tiny droplets containing the strep bacteria are
released into the air and are breathed in by other people.
Common symptoms of
strep throat in children and adults include:
mononucleosis can cause a severe sore throat that
looks like and has symptoms similar to those of strep throat. For more
information, see the topic
It is easy to
tell when you have a sore throat or a cold. It is harder to know when you have
strep throat. Typically, sore throats are caused by a
viral infection and not strep bacteria. Strep throat
usually does not occur with cold symptoms such as
coughing, sneezing, or a runny or stuffy nose. The more cold symptoms you have,
the less likely it is that your sore throat is a strep infection.
In some cases of strep infection, a skin rash develops and spreads over
the neck and chest and eventually over the whole body. The rash feels rough
like sandpaper. This condition is called
scarlet fever. Scarlet fever is treated with
antibiotics. This usually leads to a quick recovery. Scarlet fever is not
dangerous if treated.
strep throat usually begin within 2 to 5 days after
you come in contact with someone who has a strep infection. Strep throat usually
goes away in 3 to 7 days with or without antibiotic treatment. In contrast, if
allergies or irritants are the cause of your sore throat, it will usually last
longer unless the cause is eliminated.
If strep throat isn't
treated with antibiotics, you will continue to be contagious for 2 to 3 weeks
even if your symptoms go away. You are much less contagious within 24 hours after you start antibiotics and are less likely to develop complications of the strep
Complications of strep throat are rare but can occur,
especially if your throat infection isn't properly treated with antibiotics.
Complications can occur when the strep infection spreads to other parts of the
body and causes other infections, such as an ear or sinus infection or an
abscess near the tonsils (peritonsillar abscess). Complications can also result in your
immune system attacking itself and causing serious
conditions such as
Treating strep throat
can greatly reduce your risk for rheumatic fever and its
complications. It is not clear whether treating the strep infection with
antibiotics reduces your risk for inflammation of the kidneys (acute
Your risk of getting
strep throat increases if you come in close contact
with others, especially children, who have a strep infection.
size of a child's tonsils isn't a risk factor for throat infections. Children
or adults who have had their tonsils removed can still get strep throat.
Call your doctor today if you have:
Call a doctor if the following symptoms develop 1 to 2
weeks or longer after a strep throat infection. These symptoms may indicate
Call your doctor if your symptoms do not improve after 2 days of treatment with an antibiotic.
Watchful waiting is appropriate if your
sore throat occurs with symptoms like those of a cold, such as sneezing,
coughing, and a runny or stuffy nose. In general, the more of these symptoms
you have, the less likely it is that your sore throat is caused by a strep
infection. You can try home treatment if your sore throat is not severe and you
have other symptoms of a cold.
For more information on what to do if you have sore throat symptoms, see the topic Sore Throat and Other Throat Problems.
The following health professionals can evaluate a sore throat, do quick
tests or throat cultures, and prescribe antibiotic treatment if needed:
If surgery to remove chronically enlarged or infected
tonsils or adenoids is suggested, you may be referred to an
To prepare for your appointment, see the topic Making the Most of Your Appointment.
throat is diagnosed from your medical history, a physical exam of your
throat, and a lab test, such as a throat culture. Sometimes a rapid strep test is used to check for strep. Your doctor may confirm the results of the rapid strep test with a throat culture.
Current treatment guidelines recommend that your doctor confirm
strep throat with a lab test, such as a throat culture, and not diagnose strep throat just from your symptoms. But your doctor may begin treatment for strep throat before
the result of your throat culture is back if you have three or four of the following
One or both of the following tests are used to confirm that
you have strep throat.
If symptoms of strep throat are present, it is important to
be tested for strep infection. Prompt treatment will reduce the spread of strep
throat and may reduce the risk of
complications, such as the infection spreading to
other parts of your body causing ear or sinus infections or an
abscess behind or around your tonsils (peritonsillar abscess).
If you need to be
tested for strep throat, the choice between a rapid strep test and a throat
culture may not be clear. It may help to discuss with your doctor the
advantages and disadvantages of each test. For
instance, results from a rapid strep test are available within 10 to 15
minutes, and results from a throat culture may take 1 to 2 days. A throat
culture is more accurate.
Testing is not needed:
It is possible for a person to carry the strep bacteria and
not have any symptoms. If a number of infections occur in the same family, or
if there have been severe complications such as rheumatic fever or
toxic shock syndrome, it may be helpful to test
family members to learn whether they are carriers of strep infection. But it is
unusual for a person to catch strep throat from a carrier.footnote 1
Antibiotics such as
amoxicillin, cephalexin, or penicillin are used to treat
strep throat. Antibiotics work only against
bacterial infections such as strep throat. They will not
help sore throats caused by
allergies or viral infections such as colds.
Antibiotics are commonly used to:
Antibiotic treatment can begin immediately if a strep
infection is confirmed by a
rapid strep test. But there is no harm in waiting for
the results of a
throat culture to confirm strep throat before starting
antibiotic treatment. In fact, it is better to wait until strep throat has been
confirmed so that antibiotics are not used unnecessarily. Overuse of
antibiotics can make them ineffective.
Although waiting to treat strep throat may prolong
the time you have the illness, delaying treatment for a few days doesn't
increase the risk of rheumatic fever or other complications.footnote 1
Your doctor also may recommend nonprescription medicines such as acetaminophen or
anesthetic throat sprays to help relieve the pain and discomfort caused by
strep throat. Acetaminophen will also reduce fever. Be safe with medicines. Read and follow all instructions on the label.
For more information, see:
To avoid getting
strep throat, it is a good idea to avoid contact with
anyone who has a strep infection.
Wash your hands often when you
are around people with colds or
bacterial illnesses. Do not share toothbrushes or
eating and drinking utensils.
Keep up your body's resistance to infection with a good
diet, plenty of sleep, and regular exercise. Managing
stress can also strengthen your body's ability to
fight off illness, such as strep throat.
Humidify your home
during the dry winter months or year-round if you live in a dry climate.
Moisture in the air (humidity) helps keep your
mucous membranes moist and more resistant to bacteria.
You can use a humidifier in the bedroom while you sleep. But use care if a
person in the home has
allergies, because mold or other particles that
collect in the humidifier can make these conditions worse. Clean humidifiers on
a regular basis.
Stop smoking, and avoid breathing others' smoke.
Smoke irritates the throat tissues and may make you more likely to get
Your doctor may have prescribed an
strep throat. Take all of the antibiotic exactly as
prescribed. This will help prevent the infection from coming back and will
prevent complications of infection that could occur if you do not take the
medicine as prescribed.
There are many ways that you can make
yourself feel better while you are waiting for the strep infection to go
For more information on nonprescription medicines and other ways to relieve sore throat symptoms, see the topic Strep Throat: Home Treatment.
For the first 24 hours after you start taking an
antibiotic, you are still contagious. You can avoid passing the strep throat
infection to others and reinfecting yourself by:
Antibiotics are the treatment of choice
for a confirmed
strep throat infection.
Antibiotics may be
used in the following situations:
It is possible for you to carry the strep bacteria in the
throat and not have any symptoms. Antibiotics for the carrier state are usually
not needed unless you have a history of rheumatic fever or frequent infections
or infections are occurring frequently in the family.
Antibiotics such as amoxicillin, cephalexin, or penicillin are used to treat strep throat infection.
Immediate treatment with an
antibiotic after a positive rapid strep test may not make you well faster. But
it will shorten the time you are able to spread the disease to others.
Antibiotics also lower the risk of the infection spreading to other parts of
your body. But there is no harm in delaying medicine treatment 1 to 2 days to
wait for the results of a throat culture. Antibiotics will prevent rheumatic
fever even if it is started up to 9 days after symptoms begin.footnote 1
strep throat continues to recur, you and your doctor
may decide that you need surgery to remove the tonsils (tonsillectomy). Surgery is
considered when you:
Large tonsils are not an indication for tonsillectomy
unless they are causing one of the above problems or they are blocking the
upper airway, which can cause
sleep apnea or problems with eating.
Tonsillectomy may be done in some
cases of strep throat.
abscess around the tonsils (peritonsillar abscess) may be treated with a simple procedure in which a small
incision is made to drain the abscess, although removing the tonsils is
appropriate in some of these cases.
Tonsillectomy is no longer
routine for children who have frequent sore throats. Surgery has been shown to
reduce the number of throat infections for 2 years. But over time many children
who did not have surgery also had fewer throat infections.footnote 3
When you are trying to decide whether to have
your or your child's tonsils removed, consider:
The risks of surgery must also be weighed against the
risks of leaving the tonsils in. In some cases of persistent strep throat
infections, especially if there are other complications, surgery may be the
American Academy of Pediatrics (2009). Group A
streptococcal infections. In LK Pickering et al., eds., Red Book: 2009 Report of the Committee on Infectious Diseases, 28th ed., pp.
616–628. Elk Grove Village, IL: American Academy of Pediatrics.
Mar CB, et al. (2006). Antibiotics for sore throat.
Cochrane Database of Systematic Reviews (4). Oxford:
Baugh RF, et al. (2011). Clinical practice guideline:
Tonsillectomy in children. Otolaryngology–Head and Neck Surgery, 144(IS): S1–S30.
Other Works Consulted
American Heart Association (2009). Prevention of rheumatic fever and diagnosis and treatment of acute streptococcal pharyngitis: A scientific statement from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee of the Council on Cardiovascular Disease in the Young, the Interdisciplinary Council on Functional Genomics and Translational Biology, and the Interdisciplinary Council on the Quality of Care and Outcomes Research: Endorsed by the American Academy of Pediatrics. Circulation, 119(11): 1541–1551.
American Public Health Association (2008). Streptococcal diseases caused by group A (beta hemolytic)
streptococci. In DL Heymann, ed., Control of Communicable Diseases Manual, 19th ed., pp. 577–587. Washington, DC: American
Public Health Association.
Kenealy T (2014). Sore throat. BMJ Clinical Evidence. http://clinicalevidence.bmj.com/x/pdf/clinical-evidence/en-gb/systematic-review/1509.pdf. Accessed March 21, 2014.
Low DE (2012). Nonpneumococcal streptococcal infections, rheumatic fever. In L
Goldman, A Shafer, eds., Goldman's Cecil Medicine, 24th ed.,
pp. 1823–1829. Philadelphia: Saunders.
Stevens DL (2008). Streptococcal infections. In L
Goldman, D Ausiello, eds., Cecil Medicine, 23rd ed., pp.
2176–2183. Philadelphia: Saunders Elsevier.
Wessels MR (2011). Streptococcal pharyngitis. New England Journal of Medicine, 364(7): 648–655.
Wessels MR (2012). Streptococcal infections. In DL Longo et al., eds., Harrison's Principles of Internal Medicine, 18th ed., vol. 1, pp. 1171–1180. New York: McGraw-Hill.
ByHealthwise StaffPrimary Medical ReviewerKathleen Romito, MD - Family MedicineSpecialist Medical ReviewerDonald R. Mintz, MD - Otolaryngology
Current as ofNovember 14, 2014
Current as of:
November 14, 2014
Kathleen Romito, MD - Family Medicine & Donald R. Mintz, MD - Otolaryngology
How this information was developed to help you make better health decisions.
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