Haematuria in Children
Haematuria, the presence of blood in the urine, is a common clinical finding in children. It can be a benign, self-limiting condition or a sign of serious underlying renal disease. A thorough clinical assessment is crucial to differentiate between these possibilities and to identify any red flags that would prompt urgent investigation and specialist referral.
Classification
Macroscopic (Gross) Haematuria: The blood is visible in the urine, making it appear red, pink, or ‘cola-coloured’.
Microscopic Haematuria: Blood is only detectable by urine dipstick or microscopy.
Aetiology and Causes
The causes of haematuria are diverse and can be divided into renal and non-renal origins.
Renal Causes
Glomerulonephritis: This is inflammation of the glomeruli and is a key cause of macroscopic haematuria. It can be post-streptococcal, following a sore throat or skin infection, or other forms like IgA nephropathy or Alport syndrome.
Henoch-Schönlein Purpura (HSP): A vasculitis that can affect the kidneys, causing haematuria and proteinuria.
Haemolytic Uraemic Syndrome (HUS): Often follows a diarrhoeal illness and is characterised by acute kidney injury, haemolytic anaemia, and thrombocytopenia.
Hypercalciuria/Stones: High levels of calcium in the urine can cause microscopic haematuria, or in severe cases, kidney stones.
Tumour: Although rare, a kidney tumour like a Wilms’ tumour should be considered in a child with an abdominal mass.
Other Causes
Lower Urinary Tract Infection (UTI): A common cause of both macroscopic and microscopic haematuria.
Trauma or Local Irritation: Injury to the perineum or bladder, or conditions like balanitis or vulvovaginitis.
Systemic Conditions: Bleeding disorders, sickle cell disease, or even menstruation can cause haematuria.
Clinical Assessment
History
A detailed history is the most important part of the assessment.
Symptom Characteristics: Ask if the urine is ‘cola-coloured’ or if blood is only present at the end of urination.
Associated Symptoms: Enquire about dysuria, fever, loin pain, or a preceding sore throat or diarrhoeal illness.
Systemic Signs: Ask about a rash (HSP), joint pain, or swelling around the eyes (glomerulonephritis).
Family History: A family history of renal or bleeding disorders is a key consideration.
Examination
General: Check the child’s blood pressure, as hypertension can be a sign of renal disease. Assess for signs of fluid retention, such as oedema around the eyes or feet.
Systemic: Look for a purpuric rash (HSP), malar rash (lupus), or a swollen joint.
Abdomen: Palpate for a renal mass or loin tenderness. Examine the genitalia for any local causes.
Investigations
Urine Analysis: A urine dipstick is the first step. If positive, a urine microscopy is essential to confirm the presence of red blood cells. In macroscopic haematuria, a urine culture is also necessary to rule out a UTI.
Bloods: In cases of macroscopic haematuria or if a systemic cause is suspected, blood tests are required. These include U&Es (to check renal function), FBC, ESR, and a complement profile (C3, C4) to assess for glomerulonephritis.
Imaging: A renal tract ultrasound is a key investigation to check for structural abnormalities, stones, or tumours.
Management and Referral
Referral to a Paediatric Nephrologist: A referral to a specialist renal team is required for any child with:
Abnormal renal function.
Proteinuria (2+ or more on dipstick).
Hypertension.
Oedema or oliguria (reduced urine output).
Persistent or macroscopic haematuria.
A suspected systemic cause (e.g., HSP with renal involvement).
Microscopic Haematuria: If the child is otherwise well and there are no red flags, microscopic haematuria is often monitored with follow-up urine tests at 6-month intervals.
Underlying Cause: Management is aimed at treating the underlying cause, whether it’s a UTI, hypercalciuria, or a more serious condition.