Poststreptococcal disorder is a group of autoimmune disorders that occur after an infection with the bacteria Streptococcus pyogenes, also known as group A Streptococcus (GAS).
An autoimmune disorder occurs when your immune system mistakes your healthy cells as foreign and begins to attack them.
In poststreptococcal disorders, the antibodies that your immune system created to fight against GAS mistakenly start destroying your healthy cells usually after they have cleared the bacteria.
The initial infection might only cause a sore throat, fever, and rash, but poststreptococcal disorders can lead to many different problems.
The exact disorder depends on which part of the body is attacked by your immune system. The disorder can affect the kidneys, heart, skin, brain, or joints. Examples of poststreptococcal disorders include the following:
- acute rheumatic fever
- obsessive-compulsive disorders
- movement disorders such as tics and myoclonus
- kidney problems like glomerulonephritis
These disorders more commonly affect children. It may come on suddenly. There is no cure for poststreptococcal disorder, but treatments are available to help manage the symptoms and most people recover fully.
The symptoms depend on which part of the body is under attack. There are many disorders associated with GAS infections. Some are still being researched. Some of the known disorders associated with GAS include the following:
Acute rheumatic fever (ARF)
Acute rheumatic fever usually develops about two to four weeks after a strep infection. It can lead to inflammation in the joints, heart, skin, and central nervous system.
The symptoms include:
- painful joints
- swollen joints
- heart murmur
- chest pain
- uncontrollable movements
- rash or skin nodules
Most outbreaks happen in areas where people are living in overcrowded conditions and don’t have easy access to antibiotics.
Post streptococcal related myalgia
Symptoms of myalgia includes severe muscle pain and tenderness.
Sydenham’s chorea (SC)
Sydenham’s chorea is characterized by jerking and twisting movements of the limbs. These rapid movements can’t be controlled. Chorea is more common in girls and occurs more often in children ages 5 to 15 years old.
Poststreptococcal glomerulonephritis (GN)
GN may develop a week or two after a strep throat infection. It occurs when the body produces antibodies that attack the glomeruli. These are the small filtration units in the kidney that filter waste which is removed in the urine. Symptoms include:
- pink or dark urine due to blood in your urine (hematuria)
- foamy urine due to too much protein (proteinuria)
- high blood pressure
- fluid retention
- kidney failure
PANDAS stands for Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections. These disorders include obsessive-compulsive disorder (OCD) and tic disorders that appear suddenly after strep throat or scarlet fever. Symptoms include:
- motor tics (involuntary movements)
- vocal tics (involuntary sounds or words)
- obsessions and compulsions
- children may be moody, irritable, and experience anxiety attacks
Poststreptococcal disorder is caused by an infection with bacteria called Streptococcus pyogenes, also known as group A Streptococcus (GAS). The initial infection may not cause any symptoms. If you do experience symptoms, the most common are:
- sore throat (strep throat)
- swollen tonsils covered in a white coating
- tender lymph nodes
- red skin rash and reddened tongue (scarlet fever)
- impetigo: an skin infection with open sores, fever, sore throat, and swollen lymph nodes
Your immune’s system job is to defend your body against foreign invaders like the GAS bacteria. The immune system produces substances called antibodies that target and kill the foreign invaders.
The antibodies usually ignore normal healthy cells. Autoimmune diseases occur when your immune system mistakes the normal cells as the foreign invaders and begins to attack them too.
The Streptococcus bacterium is unique because it survives in the body by putting molecules on its cell wall that are almost identical to the molecules found on the skin, heart, joints, and brain tissues.
By doing this, the bacteria hides from the immune system. The immune system eventually realizes that these are foreign cells and attacks them. This is called “molecular mimicry” because the bacteria and normal tissue are similar enough that immune system mistakes normal cells for foreign, and damage to tissue can occur.
Poststreptococcal disorder happens when the antibodies that your immune system created to fight against GAS erroneously start attacking your healthy cells. The exact disorder depends on which of your organs are being attacked.
The diagnosis of poststreptococcal disorder is a clinical diagnosis. This means that there are no specific lab tests available to diagnose the conditions. Instead, your doctor will often take a full medical history and a physical examination.
They will ask if you or your child has been infected with strep throat, scarlet fever, or impetigo within the last few months. The doctor will ask about the symptoms and whether or not they came on abruptly.
If the symptoms have been present for more than a week, blood tests (antistreptococcal titers) may be done to find out if there has been a recent GAS infection.
If your doctor suspects you or your child is suffering from GN, they may recommend a urinalysis (a chemical and microscopic analysis of urine), and additional blood tests. If your doctor suspects acute rheumatic fever, you may have some tests done on your heart.
It’s important to remember that many children have tics or display signs of OCD, and many kids also get strep throat at some point. Post streptococcal disorders are not common.
Poststreptococcal disorders, like PANDAS, are only considered when there is a clear relationship between the onset of symptoms like OCD or tics, and a recent infection.
Treatment depends on the exact disorder. Since there is no cure, treatment is aimed at treating the symptoms. Antibiotics are given to make sure that the GAS infection is gone, and also to prevent acute rheumatic fever.
Treatment for ARF includes nonsteroidal anti-inflammatory drugs (NSAIDs).
Sydenham’s chorea is often not treated because the symptoms are so mild and the condition will most likely go away on its own after a few months. More severe cases of chorea may be treated with:
- intravenous immune globulin (to help get rid of the antibodies that make the symptoms worse)
Therapy and counseling may be used for emotional issues, compulsions, and other behavioral problems. Medications include the following:
- anti-anxiety medications
Acute rheumatic fever can cause permanent damage to the heart. In some cases, the inflammation from ARF may result in long-term complications, including:
- valve stenosis (narrowing of the valve, which results in decreased blood flow)
- valve regurgitation (a leak in the valve, which may cause the blood to flow in the wrong direction)
- damage to heart muscle, making it weaker
- damage to the mitral or aortic valve
- atrial fibrillation (irregular heartbeat of the upper chambers of the heart)
- heart failure
Chorea and myalgia usually will go away on their own without problems. An article in American Family Physician states that more than 95 percent of people with poststreptococcal glomerulonephritis will get better on their own within a month.
You can prevent acute rheumatic fever by receiving prompt and complete treatment with antibiotics for a strep infection. This means taking all prescribed doses on time.
You can’t always prevent poststreptococcal disorder, but you can take measures to prevent getting a strep infection to begin with. These include:
- avoiding contact with anyone who has a strep infection.
- washing your hands often
- not sharing toothbrushes or eating utensils
Strep throat is highly contagious and fairly common in children. Not all children who have a GAS infection will end up with poststreptococcal disorder.
- Hahn, R., et al. (2005). Evaluation of poststreptococcal illness. http://www.aafp.org/afp/2005/0515/p1949.html
- Ivory, D., & Folzenlogen, D. (2009). Post streptococcal
syndromes, a rheumatologist perspective.http://ispub.com/IJRH/6/2/12159
- Mayo Clinic Staff. (2020). Glomerulonephritis. https://www.mayoclinic.org/diseases-conditions/glomerulonephritis/symptoms-causes/syc-20355705
- Mayo Clinic Staff. (2019). Rheumatic fever. https://www.mayoclinic.org/diseases-conditions/rheumatic-fever/symptoms-causes/syc-20354588
- PANDAS: Fact sheet about pediatric autoimmune neuropsychiatric
disorders associated with streptococcal infections. (2019).
- Sydenham’s chorea. (2019). https://www.aboutkidshealth.ca/Article?contentid=846&language=English
- Snider, L., & Swedo, S. (2003). Post-streptococcal autoimmune disorders of the central nervous system.
- Walker, K. G., & Wilmshurst, J. M. (2010). An update on the treatment of Sydenham’s chorea: the evidence for established and evolving interventions. http://doi.org/10.1177/1756285610382063