Description
Strep throat is an infection caused by a bacteria called streptococcus pyogenes, also known as Group A strep or Group A beta-hemolytic strep (GABHS). (Strep throat is occasionally caused by Group C or G strep in adolescents; the treatment is the same). These bacteria can cause several infections in children; strep throat is by far the most common. A related infection is scarlet fever, which is really just strep throat with a rash (and is not more serious than any other case of strep throat).
Symptoms
Symptoms of strep throat can include any of the following:
- Fever
- Sore throat, often looking very red, sometimes with pus seen on the tonsils
- Headache
- Stomach ache and/or vomiting
- Swollen and/or tender lymph nodes (“glands”) in the neck
- A fine rash
The symptoms usually start suddenly; however, many children have mild symptoms and may only complain of a headache or stomach ache. Not all children with strep throat complain of a sore throat, and not all have a fever.
Note that runny nose and cough are NOT symptoms of strep, and children with these symptoms usually do not have strep throat, unless they happen to have caught a cold and strep throat at the same time.
Who gets it?
It is mostly an infection of school-age children, ages 5 to 16 years or so. It is unusual in children less than 2 years old and rare in infants. Adults can get it as well. Children who have had their tonsils removed can still catch strep throat.
Is it contagious?
Yes, it is quite contagious. Children usually develop symptoms 2-5 days after being exposed. Children with strep throat are contagious until they have been taking antibiotics for 24 hours. People do not develop immunity to strep throat, and a person can actually re-infect himself with his own germs once he stops taking the antibiotics. Therefore many people recommend sterilizing the toothbrush or getting a new one several days after starting the antibiotics but before finishing them to prevent re-infection.
How is it diagnosed?
Strep throat cannot be reliably detected by examining the child; many children with strep have very mild symptoms and normal looking throats, and many children with fever and a very red sore throat do not have strep and have a viral infection instead. Studies show that there is no reliable combination of symptoms and findings that can predict whether someone has strep throat or not. We have to rely on lab tests instead to detect whether the strep germ is present.
The first test we use is a rapid strep test, done in the office, to see if the strep germ is present. The test is accurate in over 90% of cases. Because diagnosing strep is so important (to prevent complications), when the rapid test is negative we often do a throat culture, which is the most reliable test. This test takes 2 days to see if the actual bacteria will grow in a culture. It is not harmful to wait to start treatment during these two days while waiting for the results of the throat culture.
Treatment
Surprisingly, the symptoms of Strep throat will actually resolve in many cases without antibiotics. Then why do we treat with antibiotics? Recent research has also shown that symptoms of strep throat improve a day or two faster by giving antibiotics than they would on their own. However, the main reason we treat strep throat is to prevent complications. There are some complications of the infection itself, such as abscesses in the throat. A much more serious complication is rheumatic fever, where heart valves and other organs become damaged after the initial strep infection is resolved (it is still unclear what exactly causes rheumatic fever). It has been clearly shown that treating strep infection within the first 10 days helps to prevent rheumatic fever.
Penicillin remains the antibiotic of choice for strep throat, though there is now some controversy regarding the use of other antibiotics to treat it. Penicillin can be given in the form of a shot (a very painful shot compared to other shots), or taken orally; amoxicillin is often used instead of penicillin because we use it so often for other infections. Oral antibiotics are just as effective as the shot, as long as they are given correctly. Amazingly, there is no resistance of strep germs to penicillin. Some recent research has suggested that a group of antibiotics called cephalosporins may be more effective in completely eradicating the strep germ from children’s throats. As a result, some have suggested using these antibiotics instead. However, at this time this is not recommended for several reasons: 1) cephalosporins kill more germs than is necessary and are more likely to lead to resistant germs, 2) penicillin is the only drug ever proven to prevent rheumatic fever, and 3) it is not known if completely eradicating the germ is necessary or clinically significant.
Erythromycin and related antibiotics called macrolides are also used to treat strep throat. Azithromycin (Zithromax) is a very popular drug these days, in part due to the fact that it is given for only 5 days, once a day, and also due to clever marketing by the drug company. However, strep is developing a good bit of resistance to azithromycin and it is therefore not recommended as a primary treatment for strep throat.
Fever and/or pain can be treated with acetaminophen or ibuprofen.
Soft foods may be easier on the throat. Also, if the child is vomiting, a bland diet and/or clear liquids should be used. Warm soup or apple juice are often soothing to the throat; some children find ice cream, milk shakes, and other cold drinks more soothing. Children over age 4 can suck on hard candy. There are also children’s sore throat sprays that can be helpful.
It is generally recommended that people with strep throat get a new toothbrush or sterilize their old one several days after starting antibiotics but before finishing them, so that they do not re-infect themselves once they finish their antibiotics.
Prevention
Children with strep throat are contagious until they have been on antibiotics for 24 hours, so keeping away from children with strep throat can help prevent the spread of infection. Hand washing remains the best way a person can keep from catching infectious diseases like colds and strep throat.
References
Clinical Practice Guideline for the Diagnosis and Management of Group A Streptococcal Pharyngitis: 2012 Update by the Infectious Diseases Society of America. Clin Infect Dis. first published online September 9, 2012. doi:10.1093/cid/cis629
