Post-streptococcal glomerulonephritis

What it is

Poststreptococcal glomerulonephritis is the classic example of acute glomerulonephritis, which may be due to a variety of immunologic, infectious or postinfectious causes. It presents as nephritic syndrome, one of the two clinical manifestations of glomerular disease, and it is the most common cause of nephritic syndrome in children.

It occurs after infection with a group A beta haemolytic streptococcal infection of the upper respiratory tract, or of the skin, that is impetigo, usually Streptococcus pyogenes. The GN develops about 10 to 14 days after the infection, put elsewhere as typically 7-14 days following it. It is caused by immune complex deposition, IgG, IgM and C3, in the glomeruli, and it primarily affects children, ages 2 to 6, with young children most affected. It is one of the listed complications of scarlet fever, alongside acute rheumatic fever.

The interval is not one number but two, and it follows the site of the infection: after pharyngitis or tonsillitis, which is the most common, it is 1-2 weeks, and after skin infections it is 3-4 weeks. The age band is reported as ages 2 to 6 in one source and as children between the ages of 3-12 years in another.