Postinfectious glomerulonephritis

Postinfectious glomerulonephritis (PIGN) is a type of glomerulonephritis, a group of diseases that cause inflammation and damage to the kidney's filtering units. This condition is often seen in children following an infection, particularly a streptococcal infection of the throat or skin.

Etiology

PIGN is most commonly caused by an infection with certain strains of Group A streptococcus. These bacteria are responsible for diseases such as strep throat and impetigo. Less commonly, PIGN can be caused by other types of bacteria or by viral infections.

Pathophysiology

In PIGN, the body's immune response to a streptococcal infection results in inflammation and damage to the glomeruli. This is thought to occur due to the deposition of immune complexes (combinations of antibodies and antigens) in the glomeruli.

Clinical Presentation

Symptoms of PIGN may include hematuria (blood in the urine), proteinuria (excess protein in the urine), and edema (swelling), particularly in the face and legs. Some patients may also experience hypertension (high blood pressure).

Diagnosis

Diagnosis of PIGN typically involves a combination of clinical history, physical examination, and laboratory tests. These may include a urinalysis, blood tests, and in some cases, a kidney biopsy.

Treatment

Treatment for PIGN is primarily supportive, as the condition often resolves on its own over time. This may include medications to control blood pressure and swelling, as well as dietary modifications. In severe cases, dialysis may be required.

Prognosis

The prognosis for PIGN is generally good, particularly in children. Most patients recover completely within a few weeks to months. However, in some cases, PIGN can lead to chronic kidney disease or end-stage renal disease.