Strep throat is a contagious infection caused by bacteria called Group A Streptococcus.
These bacteria can cause infections ranging from mild infections, such as cellulitis and impetigo, to more serious conditions, such as rheumatic fever, kidney problems, toxic shock syndrome, and necrotizing fasciitis. Strep throat and mild skin infections are the most common forms of illness caused by these bacteria.
Strep bacteria pass from one person to another when an infected person coughs, sneezes, or touches another person or object with a hand contaminated by infected droplets of fluid from the airways or throat. It takes two to seven days for symptoms to appear after someone has been exposed.
These are common symptoms of strep throat:
Sore throat and pain when swallowing
A red throat that's swollen and may be dotted with white or yellow pus
Swollen neck glands (lymph nodes)
Low to high fever, depending on age, possibly with chills
Headache and body aches
Loss of appetite, nausea, and vomiting
In children, symptoms may also include abdominal pain, vomiting, and a red rash with small spots worse in skin creases and under the arms.
Symptoms often appear suddenly, without a cough or cold symptoms. In fact, a cough and congested nose make it very unlikely that a person has strep throat as opposed to a viral sore throat.
If you have symptoms of strep, see your health care provider for a diagnosis. If your provider suspects a strep infection, you will probably be given a rapid strep test, which involves taking a sample of throat secretions with a cotton swab. If the test is positive, it's a strep infection. If the test is negative, the sample may be sent to a lab for a throat culture. This means trying to grow any bacteria in the sample to see if strep is present. This test usually takes 48 hours for results. Most throat infections are caused by viruses and do not need antibiotic treatment.
If the rapid strep test or the throat culture confirms strep, your health care provider will prescribe a course of penicillin or another antibiotic, which will make you better faster. Group A strep is the main bacteria to cause sore throat and the only type that needs antibiotic treatment. Within a day or so of beginning antibiotics, your symptoms should improve. You aren't considered contagious after you have been on antibiotics for 24 hours, but you must complete the entire course of medication to help prevent complications such as rheumatic fever. Take all your medication even if you feel better within a few days.
Follow these steps to prevent spreading the bacteria and infecting people:
Don't share utensils, dishes, drinking glasses, food, drinks, napkins, handkerchiefs, or towels.
Prevent the spread of fluid droplets from sneezing or coughing by covering your mouth and nose.
Wash hands frequently.
Strep infections that are left untreated or not treated completely can lead to rheumatic fever, an illness that can damage heart valves, and also may cause glomerulonephritis, a serious kidney disorder.
These steps can help you feel better, but they aren't a replacement for antibiotics:
Take acetaminophen or ibuprofen as needed for fever and body aches. Do NOT give aspirin to children because it can cause a dangerous condition called Reye syndrome.
Gargle with saltwater.
Use throat lozenges or hard candy.
Eat soft foods.
Drink plenty of liquids.
Rest in bed.
Run a cool-mist humidifier to add moisture to the air.
Place a warm, moist towel around the throat.
The fever that accompanies strep usually stops one to two days after you start taking antibiotics. The sore throat passes soon after that.
Talk to your health care provider if you have questions about strep throat.