What causes strep throat?
Strep throat is caused by streptococcal (strep) bacteria. There are many different types of strep bacteria. Some cause more serious illness than others.
Although 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.
What are the symptoms?
The most common symptoms of strep throat are:
- A sudden, severe sore throat.
- Pain when you swallow.
- Fever over 101°F (38.3°C).
- Swollen tonsils and lymph nodes.
- White or yellow spots on the back of a bright red throat.
- You may also have a headache and belly pain.
- Less common symptoms are a red skin rash, vomiting, not feeling hungry, and body aches.
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.
How is strep throat diagnosed?
Your doctor will do a physical exam, ask you about your symptoms and past health, and do a rapid strep test to diagnose strep throat. Sometimes another test, called a throat culture, is also needed.
If the rapid strep test says that you don't have strep (the test is negative) but your symptoms suggest that you do, your doctor may want to do a throat culture to be sure. This is because rapid strep tests are not always accurate. To do a throat culture, the doctor will swab a sample of cells from the back of your throat. The sample will go into a special cup (culture) where the strep bacteria can grow over time. If strep bacteria grow, the doctor knows that you have strep.
If the rapid strep test is positive and says that you do have strep, there’s no need to do the throat culture.
How is it treated?
Strep throat will go away in 3 to 7 days with or without treatment. Doctors usually treat strep throat with antibiotics even though they may not make you well faster. 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.
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 away.
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. Do not give aspirin to anyone younger than 20. It has been linked to Reye syndrome, a serious illness.
How do you prevent strep throat?
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 share toothbrushes.
Bacteria can live for a short time on doorknobs, water faucets, and other objects. It’s a good idea to wash your hands regularly.
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 antibiotics.