Group A Streptococcal Infections
Group A streptococcal (strep) infections can range from a mild skin infection or a sore throat to severe, life-threatening conditions. Most people are familiar with strep throat, which along with minor skin infections, is the most common form of the disease. Health experts estimate that more than 10 million mild infections (throat and skin) occur every year.
Untreated group A strep infections can result in rheumatic fever and post-streptococcal glomerulonephritis (PSGN).
Rheumatic fever can develop about 18 days after a bout of strep throat and causes heart disease with or without joint pain. It can be followed months later by Sydenham chorea, a disorder in which the muscles of the torso, arms, and legs move involuntarily in a dancing and jerky manner.
PSGN is an inflammation of the kidneys that may follow an untreated strep throat but more often comes after a strep skin infection.
Both disorders are rarely seen in the United States because of prompt and effective treatment of most cases of strep throat.
Group A strep infections include:
They also include severe, life-threatening strep infections such as:
- Bacteremia (bacteria in the blood)
- Toxic shock syndrome
- Necrotizing fasciitis (commonly called flesh-eating disease)
Cellulitis and Erysipelas
Cellulitis is inflammation of the skin and deep underlying tissues.
Erysipelas is an inflammatory disease of the upper layers of the skin.
Group A strep (streptococcal) germs are the most common cause of cellulitis and erysipelas.
Both cellulitis and erysipelas begin with a minor incident, such as a bruise. They can also begin at the site of a burn, surgical cut, or wound, and usually affect your arm or leg. When the rash appears on your trunk, arms, or legs, however, it is usually at the site of a surgical cut or wound.
Even if you have no symptoms, you carry the germs on your skin or in your nasal passages and can transmit the disease to others.
Symptoms of cellulitis may include:
- Your skin will be painful, red, and tender
- Your skin may blister and then scab over
- You may have perianal (around the anus) cellulitis with itching and painful bowel movements
Symptoms of erysipelas may include:
- A fiery red rash with raised borders on your face, arms, or legs
- Hot, red skin with sharply defined raised areas
In addition, the infection may come back, causing chronic (long-term) swelling of your arms or legs (lymphedema).
Your healthcare provider may take a sample or culture from your skin lesions to identify the bacteria causing infection. He or she may also recover the bacteria from your blood.
Depending on how severe the infection is, your healthcare provider will treat you with either oral or intravenous (through the vein) antibiotics.
Impetigo is an infection of the top layers of the skin and is most common among children ages 2 to 6 years. It usually starts when bacteria get into a cut, scratch, or insect bite.
Impetigo is usually caused by staphylococcus (staph) bacteria, but it also can be caused by group A streptococcus bacteria. Skin infections are usually caused by different types (strains) of strep bacteria than those that cause strep throat. Therefore, the types of strep germs that cause impetigo are usually different from those that cause strep throat.
The infection is spread by direct contact with lesions (wounds or sores) or nasal discharge from an infected person. Scratching may spread the lesions. It usually takes 1 to 3 days from the time of infection until you show symptoms. If your skin doesn’t have breaks in it, you can’t be infected by dried strep bacteria in the air.
Symptoms start with red or pimple-like lesions surrounded by reddened skin. These sores can be anywhere on your body, but mostly on your face, arms, and legs. The sores fill with pus, then break open after a few days and form a thick crust. Itching is common.
Your healthcare provider can diagnose the infection by looking at the skin lesions.
If your impetigo is caused by strep bacteria, your healthcare provider will prescribe oral antibiotics, as with strep throat. This treatment may also include an antibiotic ointment to be used on your skin.
Scarlet fever is a form of group A streptococcal disease that can follow strep throat. It is usually contagious and lasts for a specific length of time whether or not it is treated.
You can get scarlet fever through direct contact with mucus from the throat, fluid from the nose, or saliva of an infected person.
In addition to the symptoms of strep throat, a red rash appears on the sides of your chest and abdomen. It may spread to cover most of your body. This rash appears as tiny, red pinpoints and has a rough texture like sandpaper. If you press on the rash, it loses color or turns white.
Other symptoms can include:
- Dark red lines in the folds of your skin
- A bright strawberry-red tongue and flushed (rosy) face, while the area around your mouth remains unchanged
The skin on the tips of your fingers and toes often peels after you get better. If you have a severe case, you may have a high fever, nausea, and vomiting.
Your healthcare provider will treat scarlet fever with antibiotics.
Severe Strep Infections
Some types of group A strep bacteria cause severe infections, such as:
- Bacteremia (bloodstream infections)
- Toxic shock syndrome (multi-organ infection)
- Necrotizing fasciitis (flesh-eating disease)
In 2006, 4,587 cases of severe group A streptococcal disease were reported to the Centers for Disease Control and Prevention.
Those at the greatest risk of getting a severe strep infection are:
Severe group A strep disease may also occur in healthy people who have no known risk factors.
Depending on the specific strep infection, symptoms can include:
- Severe pain and swelling
- Redness at the site of a wound
- Rash over large areas of the body
Severe group A strep infections are diagnosed by healthcare providers using a combination of clinical and laboratory test results.
All severe group A strep infections may lead to shock, organ failure, and death. Therefore, healthcare providers must diagnose and treat such infections quickly.
Antibiotics used to treat these severe infections include penicillin, erythromycin, and clindamycin. If you have severe tissue damage, your healthcare provider may need to remove the tissue surgically or amputate the limb.
Strep throat is the most common throat infection caused by bacteria. It is found most often in children between the ages of 5 and 15, although it can occur in younger children and adults. Children younger than 3 years old can get strep infections, but these usually don’t affect the throat.
Strep throat infections usually occur in the late fall, winter, and early spring.
Strep throat is usually caused by group A streptococcus bacteria. Your healthcare provider may call the infection "acute streptococcal pharyngitis."
You can get strep throat by direct contact with saliva or fluids from the nose from an infected person. Most people do not get group A strep infections from casual contact with others. A crowded environment like a dormitory, school, or nursing home, however, can make it easier for the bacteria to spread. There have also been reports of contaminated food, especially milk and milk products, causing infection.
If you have strep throat infection, you will have a red and painful sore throat and may have white patches on your tonsils. You also may have swollen lymph nodes in your neck, run a fever, and have a headache. Nausea, vomiting, and abdominal pain can occur but are more common in children than in adults.
You can get sick within 3 days after being exposed to the germ. Once infected, you can pass the infection to others for up to 2 to 3 weeks even if you don’t have symptoms. After 24 hours of taking antibiotics, you will no longer spread the bacteria to others.
Your healthcare provider will take a throat swab to find out if you have strep throat infection. This will be used for a culture (a type of laboratory test) or a rapid strep test, which only takes 10 to 20 minutes. If the result of the rapid test is negative, you may get a follow-up culture, which takes 24 to 48 hours, to confirm the results. If the culture test is also negative, your healthcare provider may suspect you do not have strep, but rather another type of infection.
The results of these throat cultures will help your healthcare provider decide on the best treatment. Most sore throats are caused by viruses, and antibiotics are useless against viruses.
If you have strep throat, your healthcare provider will prescribe an antibiotic. This will help lessen symptoms. After 24 hours of taking the medicine, you will no longer be able to spread the infection to others. Treatment will also reduce the chance of complications.
Current guidelines by expert groups recommend penicillin as the medicine of choice for treating strep throat because penicillin has been proven to be effective, safe, and inexpensive. Your healthcare provider may instruct you to the take pills for 10 days or give you a shot. If you are allergic to penicillin there are other antibiotics your healthcare provider can give you to clear up the illness.
During treatment, you may start to feel better within 4 days. This can happen even without treatment. Still, it is very important to finish all your medicine to prevent complications.
Source: National Institutes of Health; National Institute of Allergy and Infectious Diseases
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 1/28/2010...#5911