MedlinePlus Medical Encyclopedia: Post-streptococcal GN

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Post-streptococcal GN

Contents of this page:
Illustrations Alternative names Definition Causes, incidence, and risk factors Symptoms Signs and tests	Treatment Expectations (prognosis) Complications Calling your health care provider Prevention

Illustrations

Kidney anatomy

Alternative names Return to top

Glomerulonephritis - post-streptococcal; Post-infectious glomerulonephritis

Definition Return to top

Post-streptococcal GN is a disorder of the kidneys. It involves inflammation of the glomeruli after infection with certain strains of the streptococcus bacterium.

Causes, incidence, and risk factors Return to top

Post-streptococcal glomerulonephritis is now an uncommon form of glomerulonephritis. It is the result of an infection, not of the kidneys, but of a remote site such as the skin or pharynx, with a specific type of Group A hemolytic streptococcus bacterium.

As a consequence of trapping immune complexes (formed from streptococcal antigen, antibodies, and complement) in the glomeruli of the kidneys, the glomeruli become inflamed, causing inefficient filtering and excreting function by the kidneys. Protein and blood may be present in the urine, and excess fluid commonly accumulates in the body. Hypertension (high blood pressure) is usually present.

Post-streptococcal glomerulonephritis now occurs less frequently because infections which may make a person vulnerable to the disorder are commonly treated with antibiotics. The disorder may develop 1 to 2 weeks after an untreated throat infection, or 3 to 4 weeks after a skin infection. It may occur in people of any age, especially children 6 to 10 years old. Although skin and throat infections are not uncommon in children, post-infectious GN is a rare complication of these infections.

Risk factors include having a recent history of sore throat, strep throat, streptococcal skin infections (such as impetigo), and other streptococcal infections.

Symptoms Return to top

Visible blood in the urine
Smoky urine
Rust-colored urine
Decreased urine output
Edema (swelling)
- Swelling of the face or eyes (common)
- Swelling of the feet, ankles, extremities
- Swelling of the abdomen
- Generalized swelling
Cough, with sputum

Additional symptoms that may be associated with this disease:

Signs and tests Return to top

An examination shows edema, especially of the face. Generalized, peripheral, or dependent edema may also appear. Circulatory congestion is common, with associated abnormal sounds heard when listening to the heart and lungs with a stethoscope (auscultation). The blood pressure is often high.

Urinalysis shows white blood cells, casts, and other abnormalities.
Urine protein may be present, but is usually less than with nephrotic syndrome.
Urine sodium may be low.
Serum ASO may be elevated.
Serum complement levels usually decrease.
Kidney biopsy confirms post-streptococcal glomerulonephritis, but biopsy is not usually necessary.
The results of an anti-DNase B test may be abnormal.

Treatment Return to top

There is no specific treatment for post-streptococcal glomerulonephritis. Treatment is focused on relief of symptoms.

Antibiotics, such as penicillin, should be used to destroy any streptococcal bacteria that remain in the body. Antihypertensive medications and diuretic medications may be needed to control swelling and high blood pressure. Corticosteroids and other anti-inflammatory medications are generally not effective.

Dietary salt restriction may be necessary to control swelling and high blood pressure.

Expectations (prognosis) Return to top

Post-streptococcal glomerulonephritis usually resolves spontaneously after several weeks to months. In a minority of adults, it may progress to chronic renal failure.

Complications Return to top

Acute renal failure
Hyperkalemia
Nephrotic syndrome
Chronic glomerulonephritis
Chronic renal failure
End-stage renal disease
Hypertension
Congestive heart failure or pulmonary edema

Calling your health care provider Return to top

Call your health care provider if symptoms indicate post-streptococcal GN may be present.

If you have experienced post-streptococcal GN, call your health care provider if decreased urine output or other new symptoms occur.

Prevention Return to top

Adequate treatment of known streptococcal infections may prevent post-streptococcal glomerulonephritis.

Update Date: 1/19/2004

Updated by: Irfan A. Agha, M.D., Department of Medicine, St. Louis University, St. Louis, MO. Review provided by VeriMed Healthcare Network.

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