Dr Jennifer Curry, Dr Ellen Barnard, Dr Victoria Livingstone; consultant review Dr Shilpa Shah
Ben, a 5 year old boy comes to the emergency department with his mum after she noticed what seems to be some blood in his urine. On taking a further history, you find out that Ben has had dark urine for 3 days. He has no pain while passing urine, and no abnormal flow of urine. He has recently been well, aside from a sore throat 10 days ago. Ben is a generally healthy child, with no past medical history. He was born at term via a normal vaginal delivery. There have been no developmental concerns. He’s had all his vaccines.
On examination he appears clinically well, with a non-tender abdomen. He has no rashes. He does look somewhat ‘puffy’ around the eyes. His throat is red with no pus on tonsils and ears are normal. His blood pressure is 118/ 70. For his age, that is an elevated blood pressure at the 95th centile. On urine dip stick there are 4+ Red cells and 1+ protein. A laboratory urine analysis confirmed >200 red cells per high power field. Renal function is normal.
So, what do we think so far?
Let’s start with the definition of Haematuria
Haematuria is defined asThe presence of 10-50 RBCs/µL may suggest underlying pathology, but significant haematuria is generally considered as > 50 RBCs/HPF
So that’s settled then. But is red, rose or tea coloured urine always Haematuria?
Not quite! For example an interesting phenomenon called beeturia – where the pigment of beetroot is found in urine, can be mistaken for haematuria! Similarly, other drugs such as rifampicin can cause discoloured urine. So, always confirm suspected haematuria by sending urine to the laboratory.
Here is a table which summarises this:
The other thing worth remembering is Macroscopic haematuria is when we can visibly see a discoloured urine (red, rose, tea coloured) and microscopic haematuria is the one where the urine looks clear but when sent to the laboratory for analysis we find >5 red cells on HPF.
How about the causes of haematuria?
Most commonly the causes include: urine tract infection and irritation or injury to the urethra or perineum. Other less common causes include: kidney stones, coagulopathies, glomerular disease, malignancies and drug induced causes. Recent vigorous exercise is a well-established cause of both microscopic and macroscopic haematuria – possibly due to renal ischaemia due to shunting of blood to muscles or lactic acidosis increasing glomerular permeability, allowing passage of erythrocytes into the urine.
So… what next?
As we all know a good history is the key to narrowing down the differential and investigating appropriately. Things to specifically ask about are:
- Trauma – sometimes this is obvious but there may be occasions it may not be quite so apparent. Think about zipper injuries – they do happen
- Pain – this can be radiating or non-radiating pain. The former could point to renal stones in that classical ‘loin to groin’ pattern. The latter could suggest acute pyelonephritis, usually accompanied with fever and being systemically unwell
- The colour! As the title suggests – Red, rose or tea colours can help identify where the blood originates. Glomerulonephritis is generally associated with brown coloured urine (Tea or coke if you prefer) while bleeding from the lower tract more likely to be rose! It’s worth remembering that the colour is not directly proportional to the amount of blood loss. It takes very little blood to make the urine go Rose!
- The past – think about recent infections, particularly throat or skin infections. These could hint at a nephritis type picture. Have they had symptoms before? What was the outcome?
- Everyone needs basic observations completed, but blood pressure is sometimes missed out. Always check BP – low BP can point to blood loss and trauma, high BP can make us think of nephritis.
- Does the child have a ‘puffy look’ – think of oedema and glomerular disease.
- Rashes! Think HSP (Henoch Schonlein Purpura).
- Abdominal and genital exam – to rule out a mass or trauma to the perineum or meatus.
- Weight, height and body mass index – important for fluid balance, drug calculations and oliguria levels.
We’ve already established that blood is present via urinalysis – look for the other clues here too. For example nitrites and leucocytes may indicate a urinary tract infection. Remember to send a culture!
- Urea, creatinine and electrolytes – Creatinine may be elevated with renal impairment caused by glomerulonephritis
- Complement C3 levels – if low this could be consistent with a diagnosis of post streptococcal glomerulonephritis or lupus nephritis.
- Full Blood Count – to check haemoglobin levels and platelets.
- Albumin levels
- ASOT/ANA levels – may be dictated by history.
This is usually only needed if you suspect the cause is trauma or a kidney stone. Depending on the differential, ultrasound or CT scan may be indicated.
We all love an algorithm
Unfortunately, there is no ‘one shoe fits all’ type picture to this presentation due to the variety of causes! Treating the cause as per the diagram above is the simplest approach. You may also have to involve nephrology.
Back to Ben
After some further blood tests we found that Ben had a significantly elevated ASOT, a low complement and a normal renal function. He was therefore diagnosed as Post Streptococcal Glomerulonephritis. He is treated with Penicillin V and blood pressure and fluid intake were monitored. He was discharged within a few days and on follow up, his blood pressure normalised within a few weeks, there was no proteinuria, and the haematuria cleared slowly. He has remained well since.
Always confirm that the discoloration is actually blood..!
History is key and directs further investigation and management
If in doubt – give your friendly local nephrologist a call!
Dr Jennifer Curry (ST7 Paediatrics), Dr Ellen Barnard (Paediatric locum), Dr Victoria Livingstone (GPST2). Craigavon Area Hospital Northern Ireland. Peer review Shilpa Shah Consultant Paediatrician Craigavon Hospital
- Clinical Evaluation of the Child With Hematuria Francisco X. Flores Nelson Textbook of Pediatrics, Chapter 536
- Haematuria in Children – PAEDIATRIC INNOVATION, EDUCATION AND RESEARCH NETWORK (piernetwork.org)
- Patel HP, Bissler JJ. Hematuria in children. Pediatr Clin North Am 2001; 48:1519.
- Gillion Boyer O. Evaluation of gross hematuria in children. In: UpToDate. (Accessed 26/11/2021