Post-streptococcal GN Health Article

Definition

Post-streptococcal GN is a disorder of the kidneys that occurs after infection with certain strains of Streptococcus bacteria.

Alternative Names

Glomerulonephritis - post-streptococcal; Post-infectious glomerulonephritis

Causes, incidence, and risk factors

Post-streptococcal GN is a form of glomerulonephritis. It is the result of an infection, not of the kidneys, but of a completely different area, such as the skin or throat, with a specific type of Group A hemolytic streptococcus bacteria.

The infection causes the tiny blood vessels called glomeruli in the kidneys to become inflamed, making the kidneys less able to filter and remove wastes.

Post-streptococcal glomerulonephritis is uncommon these days because infections that can lead to the disorder are commonly treated with antibiotics. The disorder may develop 1 - 2 weeks after an untreated throat infection, or 3 - 4 weeks after a skin infection.

It may occur in people of any age, but most often occurs in children ages 6 - 10. Although skin and throat infections are not uncommon in children, post-streptococcal glomerulonephritis is a rare complication of these infections.

Risk factors include:

• Sore throat
• Strep throat
• Streptococcal skin infections (such as impetigo)

Symptoms

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

Other symptoms that may be associated with this disease:

• Joint pain
• Joint stiffness

Signs and tests

• Abnormal sounds are heard when listening to the heart and lungs with a stethoscope (auscultation)
• Anti-DNase B test may be abnormal
• Blood pressure is often high
• Examination shows swelling (edema), especially of the face
• Kidney biopsy confirms post-streptococcal glomerulonephritis (although biopsy is not usually necessary)
• Serum ASO may be raised
• Serum complement levels usually decrease
• Urinalysis shows protein and blood in the urine