Acute glomerulonephritis is a kidney disease of sudden onset characterized by inflammation of the small filtering units in the kidneys known as glomeruli.

The child with acute glomerulonephrits can present with:

• Swelling around the eyes
• Discoloured urine – red, tea or coffee coloured urine
• Reduced urine volume
• Symptoms of High blood pressure e.g. headache and convulsions

Causes of acute glomerulonephritis:

• **Post streptococcal infection is the commonest cause of acute glomerulonephritis in children. By definition this means that there is prior infection of either the throat or skin by streptococcal bacteria.
• Other infections that can lead to acute glomerulonephritis include other bacterial, viral or parasitic infections.
• Other rare causes include Connective tissue disease eg systemic lupus erythematosus (SLE), eg IgA nephropathy or Henoch Schonlein Purpura.

** The commonest cause of AGN in children is post streptococcal infections; hence Post streptococcal Glomerulonephritis is also used synonymously with AGN.

Clinical features of acute Post streptococcal Glomerulonephritis.

• There is usually a preceding history of sore throat or skin infection few days or weeks before the swelling around the eyes.
• High blood pressure
• The other severe but uncommon complications are :
  • hypertensive encephalopathy (very high blood pressure with fits)
  • severe kidney failure
  • pulmonary oedema (retention of excessive water in the lungs)

Investigations for the child presenting with glomerulonephritis

• The urine is checked to detect the presence of blood and protein
• Blood tests:
  • Kidney function test
  • Complete blood count
  • Anti streptolysin O titre, ASOT (detects antibodies against streptococcal antigen). If positive it is suggestive of a recent infection by streptococcal bacteria
  • Complement C3 & C4 level – a low level of complement C3 is expected but this usually normalizes by 6 weeks. C4 levels are normal.

Management

• This is self limiting condition hence the management is mainly supportive depending on the severity of the condition.
• It is important that an accurate record of the daily total fluid intake and urine output is kept Regular blood pressure and weight are also monitored
• Fluid intake is usually restricted in the initial stages until the urine output increases. A diuretic drug eg frusemide may be used for control of hypertension & fluid overload
• A low salt and normal protein diet is sufficient
• A 10 day course of oral Penicillin V or erythromycin is usually prescribed to eradicate any residual streptococcal infection

Course of the disease:

• The impaired kidney function, fluid retention and high blood pressure usually resolve by 2 to 3 weeks. Hence it is important that supportive management be given till symptoms resolve.
• For the urinary abnormalities; urine colour usually normalizes by 3 weeks but blood detected only on urine examination can persist up till 1 year. Small amounts of protein can also be detected in the urine up till 6 months after the initial illness.
• Kidney biopsy is only needed in patients with severe kidney failure and those whose symptoms and signs do not resolve within the expected time frame given above.

Prognosis:

• Prognosis is very good with more than 90% of children recovering fully with no residual renal damage.
• About 2% will develop chronic kidney disease following post strep GN and should be referred to a nephrologist for further evaluation.
• All patients should be followed up for about 1 year to ensure that the kidney function, BP are normal and the urine is completely clear of protein and blood.