Post-streptococcal GN

Post-streptococcal GN

Definition:

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

Alternative Names:

Glomerulonephritis - post-streptococcal; Post-infectious glomerulonephritis

Causes, incidence, and risk factors:

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 characteristically is present.

The disorder is now less common because of the more common use of antibiotics for predisposing infections. It may occur in people of any age, especially children 6 to 10 years old. The disorder may develop 1 to 2 weeks after a throat infection, and 3 to 4 weeks after a skin infection. 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:

Visible blood in the urine
Smoky urine
Rust-colored urine
Urine output, decreased
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:

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-DNAase B test may be abnormal.

Treatment:

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):

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

Complications:

Calling your health care provider:

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:

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

Review Date: 1/19/2002
Reviewed By: Andrew T. Koren, M.D., Department of Nephrology, NYU-Mount Sinai Medical Center, New York, NY. Review provided by VeriMed Healthcare Network.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 2003 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.