Definition Group A streptococcal infections include strep throat, scarlet fever, and others.
What is going on in the body? Strep throat is the most common of the many infections that caused by group A streptococci (GAS). The symptoms of strep throat are:
pus on the tonsils (sometimes)
swollen lymph nodes in the neck (sometimes)
The infection will usually get better without treatment. However, antibiotics should be used to prevent the complications of strep throat. Some of these complications are called nonsuppurative, because they do not form pus. Rheumatic fever and glomerulonephritis, or inflammation of the kidney, are nonsuppurative. Suppurative, or pus-forming, complications of GAS include abscesses in the throat. An abscess is a collection of pus.
Scarlet fever causes a sandpaper-like rash. It usually occurs in people who have strep throat. It can sometimes occur with skin infections or other GAS infections. Scarlet fever should be treated with antibiotics to prevent the nonsuppurative complications.
The skin is another common site of GAS infection. Infection can be superficial, as with impetigo. Impetigo is an infection of the skin's surface. It can also be more involved, as with cellulitis. Cellulitis is an infection in skin and the tissues beneath it. Necrotising fasciitis is a severe form of cellulitis that destroys the infected tissue. Kidney inflammation can follow GAS skin infections, but rheumatic fever does not.
Other sites of GAS infection are:
bones and joints
Some GAS infections, especially blood infections, can be severe. These infections can be associated with streptococcal toxic shock syndrome. In this syndrome, blood pressure drops and the liver, kidney, lungs, and clotting system can fail to work properly.
What are the causes and risks of the infection? GAS infections are caused by the bacteria Streptococcus pyogenes. People who have underlying diseases such as diabetes can have more serious infections. Those with weakened immune systems are at higher risk. Chickenpox infection in children is now known to be a risk for serious GAS disease.
What can be done to prevent the infection? The infection can be spread from person to person. Prompt diagnosis and treatment is the best way to prevent the disease and its complications. Anyone with a GAS infection should take antibiotics for at least 24 hours before returning to work, school, or daycare.
How is the infection diagnosed? Infected material from the throat, blood, or a wound can be cultured. A culture is a sample that is tested for bacterial growth. Throat swabs are often used. Rheumatic fever and kidney inflammation are often diagnosed because of symptoms. If the body shows an increase in antibodies to strep organisms, a strep infection may be present.
What are the long-term effects of the infection? There are some long-term effects of a step infection:
Sometimes when infection of soft tissue is very severe, disfigurement can occur. A severe infection can also result in death.
Rheumatic fever and kidney inflammation can cause heart and kidney damage.
What are the risks to others? Anyone with an untreated strep infection can spread it to others.
What are the treatments for the infection? Penicillin is the usual treatment for GAS infections. To prevent the complications of GAS infections, it is important to take all the antibiotics prescribed.
What are the side effects of the treatments? The more common side effects of penicillin are
What happens after treatment for the infection? Most GAS infections respond rapidly to treatment. Once the antibiotics are finished and symptoms resolve, no further treatment is usually needed. Further treatment may be needed if long-term effects, such as kidney damage, occur due to the infection.
How is the infection monitored? Usually, monitoring is only short-term, to make sure the infection has cleared. In the case of a simple GAS throat infection, no follow up or possibly one follow up visit is usually all that is required. Other monitoring may be needed for more serious infections or complications, such as heart damage.
Author: Danielle Zerr, MD Reviewer: eknowhow Medical Review Panel Editor: Dr John Hearne Last Updated: 14/12/2004 Contributors Potential conflict of interest information for reviewers available on request
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