A streptococcal infection may lead to other diseases, such as acute rheumatic fever, pediatric autoimmune neuropsychiatric disorders, and post-streptococcal glomerulonephritis.

Group A beta-hemolytic Streptococcus is a type of bacteria that can cause a range of infections. Medical professionals often refer to these infections as “streptococcal infections.”

Streptococcal infections include:

A streptococcal infection can cause several postinfectious diseases. Medical professionals may refer to these diseases as “post-streptococcal disorders.”

This article explains the different types of post-streptococcal disorders. It also discusses their causes, diagnosis, treatment, and more.

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Below, we outline the symptoms of different post-streptococcal disorders.

Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS)

PANDAS is a condition that most commonly affects children ages 3 years old into puberty.

PANDAS causes obsessive-compulsive disorder (OCD), a tic disorder, or both. It may also cause these symptoms to worsen in children who already have them.

Symptoms of PANDAS include:

  • OCD symptoms
  • a tic disorder
  • dramatic ups and downs in the severity of OCD and tics
  • neurological abnormalities, such as physical hyperactivity or involuntary jerky movements
  • a very abrupt onset or worsening of symptoms

Acute rheumatic fever

Acute rheumatic fever is a condition that can affect the:

  • heart
  • joints
  • brain
  • skin

Acute rheumatic fever is an inflammatory condition. This means it occurs when a person’s immune system mistakenly attacks healthy cells in the body.

When this happens, it causes inflammation. This inflammation is what causes the symptoms of acute rheumatic fever.

Common symptoms of rheumatic fever include:

In rare cases, a person can develop nodules, which are painless lumps, near their joints. Another rare symptom is the development of a ring-like rash.

If left untreated, acute rheumatic fever can lead to rheumatic heart disease.

Rheumatic heart disease can be serious. It weakens the valves between the chambers of the heart.

Severe rheumatic heart disease may require heart surgery. The disease may be life threatening.

Post-streptococcal glomerulonephritis (PSGN)

PSGN is a rare kidney disease that can develop after a streptococcal infection. It is more common in children than in adults.

PSGN is also an inflammatory disease. It causes a rapid deterioration of kidney function due to an inflammatory response after a streptococcal infection.

Common symptoms of PSGN can include:

  • dark, reddish-brown urine
  • swelling:
    • in the face
    • around the eyes
    • in the hands and feet
  • a decreased need to urinate
  • urinating for a decreased amount of time
  • fatigue

In some cases, a person with PSGN may have no symptoms or symptoms that are so mild they do not seek medical help.

Streptococcal infections can cause a person to develop a post-streptococcal disorder.

Streptococcal bacteria can survive inside a person’s body by hiding from the immune system. The bacteria do this by placing molecules on their cell wall.

The molecules cause them to appear almost identical to molecules found on a person’s:

  • heart
  • joints
  • skin
  • brain tissues

Medical professionals refer to this ability to hide as “molecular mimicry.” It prevents a person’s immune system from immediately detecting the bacteria.

Eventually, a person’s immune system recognizes the molecules of the streptococcal bacteria as foreign to the body. It then produces antibodies to attack the bacteria via an immune response.

However, a person’s immune system may also mistakenly attack the body’s own molecules that the bacteria mimicked. When the body mistakenly attacks its own cells, this causes inflammation. In turn, a person develops various types of post-streptococcal disorders.

Risk factors for PANDAS

Several factors can increase the risk of PANDAS, including:

  • having repeated streptococcal infections
  • a family history of autoimmune disease
  • a family history of rheumatic fever

PANDAS also most commonly affects males and children 3–12 years old.

Risk factors for acute rheumatic fever

Risk factors for acute rheumatic fever include:

  • Age: Rheumatic fever is most common in children 5–15 years old. It is very rare in children younger than 3 years old and adults.
  • Group settings: Crowded conditions can increase a person’s risk of developing a streptococcal infection. This can then increase their chances of developing acute rheumatic fever. Crowded settings that may increase a person’s risk include:
    • busy schools
    • busy day care centers
    • military training facilities
    • overcrowded living spaces
  • Lack of access to primary healthcare: People who lack access to primary healthcare may have an increased risk of developing acute rheumatic fever.
  • Drinking sugary beverages: People who regularly consume sugar-sweetened beverages have a higher risk of developing acute rheumatic fever.

Causes and risk factors for PSGN

Risk factors for PSGN include:

  • age, as PSGN is more common in children than in adults
  • poor hygiene
  • overcrowding
  • a family history of PSGN

Diagnosis varies depending on the post-streptococcal disorder.

Diagnosing PANDAS

There are no lab tests doctors can use to diagnose PANDAS.

Instead, doctors use the following diagnostic criteria to diagnose PANDAS:

  • the presence of:
    • OCD
    • a tic disorder
    • or both of the above
  • symptoms that develop between the ages of 3 years and puberty
  • dramatic ups and downs in the severity of OCD and tics
  • association with a streptococcal infection
  • association with neurological abnormalities, such as physical hyperactivity or involuntary jerky movements
  • the very abrupt onset or worsening of symptoms

If a child has symptoms of PANDAS for over a week, a doctor may order a blood test to see whether the child had a preceding streptococcal infection.

Diagnosing acute rheumatic fever

There is no single test for the diagnosis of acute rheumatic fever. Instead, a doctor takes a person’s symptoms and medical history into account.

Additionally, a doctor wants to determine whether a person has had a streptococcal infection. They may use a throat swab or a blood test to detect a previous infection.

A doctor may also use one of the following tests to analyze how well a person’s heart is working:

  • Electrocardiogram (EKG): An EKG is a test that can determine the heart’s rhythm and measure its electrical activity.
  • Echocardiogram: An echocardiogram is a type of ultrasound test that uses high frequency sound waves to make pictures of the heart.

Diagnosing PSGN

Doctors diagnose PSGN by reviewing a person’s medical history and ordering certain lab tests.

Doctors look to see whether a person has recently had a streptococcal infection since it causes PSGN to develop.

A doctor may order urine tests to look for certain proteins and blood in the urine.

A doctor may also use a blood test to see whether they can determine how well a person’s kidneys are functioning.

If a person’s streptococcal infection is still present, a medical professional usually treats it with antibiotics.

Treatments for the different post-streptococcal disorders vary.

Treating PANDAS

If a child has OCD symptoms of PANDAS, they may benefit from behavioral therapies, such as cognitive behavioral therapy (CBT).

A child may also benefit from treatment with selective serotonin reuptake inhibitors (SSRIs). In some cases, a person may receive both CBT and SSRIs.

Intravenous immunoglobulin (IVIG) treatment may also help. IVIG can help treat PANDAS in children who have severe symptoms.

Possible side effects of IVIG include:

Treating acute rheumatic fever

Doctors may treat acute rheumatic fever with:

A doctor may also prescribe other medications to reduce severe involuntary movements.

Treating PSGN

Treatment for PSGN often aims to manage symptoms.

Doctors often recommend limiting salt and water intake to help decrease swelling. They may also prescribe diuretic medications to help reduce swelling.

A doctor may also prescribe certain medications to help manage high blood pressure associated with PSGN.

If a person has symptoms of post-streptococcal disorder following a streptococcal infection, they should receive medical attention.

An accurate diagnosis can help a doctor recommend appropriate treatment to help prevent further complications.

A post-streptococcal disorder is a disease that occurs due to a previous streptococcal infection.

These diseases include acute rheumatic fever, PANDAS, and PSGN.

In some cases, the immune system attacks the body’s own cells mimicked by streptococcal bacteria, causing post-streptococcal disorder.