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.
- 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 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.
|Last reviewed||:||19 June 2014|
|Content Writer||:||Dr. Lee Ming Lee|
|Accreditor||:||Dr. Lim Yam Ngo|
|Reviewer||:||Dr. Aina Mariana bt. Abdul Manaf|