Strep Throat

Medically Reviewed by Poonam Sachdev on February 15, 2023
7 min read

Strep throat is an infection of the throat and tonsils caused by a bacteria called group A streptococcus, which is also known as Streptococcus pyogenes. This bacteria lives in the nose and throat. You can get the infection from someone who is carrying strep A bacteria or is sick from it.

Anyone can get strep throat, but it's most common in children and teens. 

The bacteria that cause strep throat pass easily from person to person through close contact.

Strep throat spreads when someone who has the infection coughs or sneezes. Droplets filled with bacteria spray into the air.

You can give yourself strep throat (or catch it from someone else) if you:

  • Breathe it in
  • Touch something these droplets land on, such as a doorknob or table, and then rub your eyes, nose, or mouth
  • Share personal items such as a fork or spoon, glass, or toothbrush with someone who is sick
  • Kiss a person who has it

When you get infected, you typically start to show symptoms about 2 to 5 days after you were exposed to the bacteria.

You can stay contagious for up to a month if you don't get treated. Antibiotics can prevent the infection from spreading. People who take antibiotics stop being contagious after about 24 hours.

A sore throat is the main sign you or your child has strep. Colds and other viruses can also cause a sore throat. One way to tell the difference between strep throat and another virus is that a virus will often cause a runny nose, too.

With strep, the sore throat comes on quickly and is more likely to cause these other symptoms. Call your doctor if you or a child in your care has these symptoms:

  • A fever of 101 F or higher

  • Red, swollen tonsils

  • Pain when you swallow

  • Swollen and/or tender lymph nodes at the front of your neck

  • White patches in the throat

  • Tiny red spots on the roof of the mouth (called petechiae)

  • Appetite loss

  • Stomachache

  • Headache

  • Body aches

  • Nausea or vomiting

  • Loss of appetite

  • Rash

Signs that the infection might be viral rather than caused by strep bacteria include:

  • Cough

  • Runny nose

  • Hoarse voice

  • Pinkeye (also called conjunctivitis)

To see whether you have strep throat, contact your health care professional. They'll will ask about your or your child's symptoms. The only sure way to tell strep from viruses that cause a sore throat is to do a test. There are two kinds of strep throat tests:

Rapid strep test: It can identify a case in just a few minutes. The doctor will gently hold down your or your child's tongue with a depressor. Then, they will swipe a cotton swab around the back of the throat.

You'll get the results in 20 minutes or less. If the test is positive, which means strep is there, the doctor may prescribe antibiotics to treat it.

If the test is negative, that means they didn't find strep bacteria. Your doctor might send the sample to a lab for a follow-up test that takes longer.

A rapid strep test can be positive if you have a sore throat that's caused by a virus. It can be difficult to tell what's causing the sore throat in that situation because you're carrying the bacteria and a virus. If you keep getting a sore throat after taking antibiotics, you (or your child) could have a viral throat infection and be a strep throat carrier. You might be less likely to spread it to other people, though.

Throat culture: The doctor will rub a swab over the throat and tonsils to be sent to the lab. If you or your child has strep throat, the streptococci bacteria will grow in it.

It usually takes about 2 days to get results from a throat culture. It can confirm whether it's strep throat or not.


Your doctor may prescribe antibiotics to kill the bacteria that cause the infection. Most treatments last about 10 days. The medicine can make symptoms go away faster and help prevent complications.

If you or your child has a positive test but no symptoms, you're probably just a carrier. In that case, you're less likely to spread the bacteria to others, and unlikely to have complications. So you probably won't need antibiotics. Your doctor can let you know if you need them or not.

Make sure you or your child takes all of the doses. Stopping the medicine too early can leave some bacteria alive. These can make you or your child sick again. Be sure to tell the doctor if you or your child is allergic to any types of antibiotics.

If the strep test is negative, a virus likely caused the sore throat. Antibiotics won't be needed because these medications don't kill viruses.

You can take medications to ease the pain of strep throat and lower fever, including over-the-counter medicines such as ibuprofen or acetaminophen. Don't give aspirin to children or teens. It can cause a rare but dangerous condition called Reye’s syndrome



There are a number of things you can do at home to lessen pain and make you feel more comfortable:

  • Gargle with a mixture of a quarter-teaspoon of salt and 8 ounces of warm water.
  • Suck on a throat lozenge or piece of hard candy. But don't give small pieces of candy to children younger than 4.
  • Throw out your toothbrush and use a new one.
  • Drink warm liquids such as tea and broth, and drink plenty of water to prevent dehydration .
  • Suck on something cold such as an ice pop or ice chips.
  • Choose soft foods that are easy to swallow such as soups, applesauce, or oatmeal. Pass on orange juice and other drinks that have a lot of acid. They'll sting.
  • Honey can help ease pain and inflammation.
  • Use a humidifier and/or saline nasal sprays to keep your airways moist, which can help you feel more comfortable.
  • Get lots of rest so your body can recover from the infection.

The best way to avoid strep is to stay away from anyone who looks or sounds sick. Signs of strep throat can include:

  • A sore throat
  • Swollen glands
  • Fever
  • Nausea or vomiting
  • Rash

Try not to share any personal items with someone who is sick. This includes:

  • Cups and plates
  • Knives, forks, and spoons
  • Toothbrushes
  • Food and drinks

If you have strep, here are some things you or your child can do to avoid getting sick again:

  • Take all the medicine your doctor prescribed, even if you start to feel better. Some bacteria may live and rebound if you stop the medication too soon.
  • Once you've been on antibiotics for 2 to 3 days, throw out your old toothbrush and get a new one.
  • Stay out of work or school for at least 24 hours after you start taking an antibiotic.
  • Wash your hands and your children's hands often. Or use an alcohol-based hand sanitizer several times a day. Always clean your hands before you eat and after you use the bathroom. 
  • Ask your children to cover their mouths with a tissue or sleeve whenever they cough or sneeze. 

Strep complications are rare today, thanks to better diagnosis and treatment. But untreated strep throat can cause serious diseases, such as:

  • The infection spreading to the tonsils, sinuses, middle ear, the mastoid bone behind the ear (mastoiditis), skin, or blood

  • A peritonsillar abscess – it's a collection of pus around the tonsils or behind the throat that can be extremely painful

Other strep complications involve an inflammatory response in different parts of your body, including:

  • Scarlet fever, a red rash that can be tiny pin pricks that are hard to see or intense redness on the body that gives it its name

  • Rheumatic fever, which can damage the heart, brain, and joints

  • A kidney disease called glomerulonephritis

  • Poststreptococcal reactive arthritis, which is inflammation in your joints

Another rare complication that is not well-understood is a condition called PANDAS, which stands for pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections. It usually involves developing the tics and habits of obsessive compulsive disorder (OCD) after a strep infection. Symptoms of OCD can worsen after a strep infection, too.

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