Haematuria in children
BMJ 2024; 387 doi: https://doi.org/10.1136/bmj-2022-072501 (Published 25 November 2024) Cite this as: BMJ 2024;387:e072501
- Alok Godse, consultant paediatric surgeon and urologist1,
- Yincent Tse, consultant paediatric nephrologist2,
- Abosede Kokumo, general practitioner3,
- Christian Harkensee, consultant in paediatric immunology and infectious diseases4
- 1Department of Paediatric Surgery, Great North Children’s Hospital, Newcastle upon Tyne, UK
- 2Department of Paediatric Nephrology, Great North Children’s Hospital, Newcastle upon Tyne, UK
- 3Second Street Surgery, Bensham, Gateshead, UK
- 4Department of Paediatrics, Dumfries and Galloway Royal Infirmary, Dumfries, DG2 8RX, UK
- Correspondence to: C Harkensee c.harkensee{at}gmx.net
What you need to know
Visible haematuria in children can be caused by many individually rare conditions; a small number of investigations can help to identify those which require urgent action
Isolated non-visible haematuria is common and usually transient; the yield from investigations is very low
Ongoing symptomatic visible haematuria should be referred urgently for hospital investigation. Non-visible haematuria with proteinuria should also be referred
A 12 year old boy presented with a history of recurrent frank haematuria. He reported three or four episodes in the past three months, with each episode quickly fading after a couple of days. On detailed questioning, he revealed that, during each episode, he experienced transient mild dysuria, urinary frequency, urgency, and central abdominal discomfort. Abdominal examination revealed no tenderness, his foreskin was retractable, and no meatal inflammation or excoriation was visible. In clinic his urine looked clear yellow with no visible blood. Urine dipstick revealed 3+of blood.
What is haematuria?
Visible haematuria (macroscopic) is visible bloody discoloration of urine. With easy availability of urine dipstick tests, the incidental discovery of persistent (defined as more than 6 months) non-visible haematuria (microscopic haematuria or NVH) may also occur. Visible haematuria is rare, and its incidence is unknown, whereas non-visible haematuria has been found in up to 5% of school children on mass screening in Asian schools,12 with up to 0.5% persisting three to six months later.
Unlike in adults, underlying malignancy as a cause of haematuria in children is extremely rare (<0.1%).345 Although the underlying cause cannot be determined by whether the haematuria is visible or non-visible, isolated non-visible haematuria is most commonly idiopathic, whereas visible haematuria may stem from the kidney (such as IgA nephropathy or autoimmune disease) or the urinary tract (such as posterior urethritis, urinary tract stones, balanitis, or urinary tract infection46). It would, however, be unusual for haematuria to be the only feature of clinical conditions such as urinary tract infection or glomerulonephritis.1
Observational studies of patients presenting to tertiary care settings with visible haematuria identified clinically significant findings such as dysuria, colicky abdominal pain, and signs of urinary tract infection in 62% of cases.12 Whether non-visible haematuria should be investigated is being debated because of the potential risk of end stage kidney failure, mainly as a result of glomerulopathies presenting decades later. One cohort study, following young adults after compulsory military service medicals in Israel, found that, among those with persistent (on three sequential tests over six months) isolated non-visible haematuria without proteinuria and normal creatinine, 0.7% eventually developed end stage kidney failure over 20 years of follow-up, compared with 0.05% of those without haematuria.7
There are no accepted evidence-based guidelines on how to investigate and manage haematuria in children, resulting in an abundance of investigations that rarely change management. Existing guidelines are mainly from expert tertiary paediatric opinion with no economic evaluation or incidence data for primary care. Here we present a pragmatic approach derived from available literature, guidelines from the National Institute for Health and Care Excellence (NICE),89 and expert views from a general practitioner, general paediatrician, paediatric nephrologist, and a paediatric urologist.
What should I look for on history and examination?
Table 1 lists the key clinical features and relevant investigations for visible haematuria. Notable points to consider for patients with visible and non-visible haematuria are:
Key clinical features and suggested investigations for visible haematuria
Do a general paediatric examination, measure weight, height, body mass index (BMI), and blood pressure.10
Examine patients for peripheral oedema suggestive of protein loss or fluid retention.
Examine the back of legs for non-blanching purpuric rash suggestive of IgA vasculitis, (formerly called Henoch-Schönlein purpura).
Examine genitalia for signs of vulvovaginitis in girls and bleeding or white scarring of the foreskin suggestive of balanitis xerotica obliterans in boys. Both can stain blood into the urine or underwear.
Post-infectious and IgA nephropathy are the most common causes of inflammatory haematuria—take a careful infection history of preceding weeks. Explore other symptoms and signs of autoimmune nephritis as in table 1.
Be suspicious of reports of recurrent visible haematuria, especially if accompanied by other medically unexplained symptoms or unexplained genital trauma and take safeguarding advice as appropriate. If factitious or induced illness is suspected as a cause of reported haematuria, advice must be sought from local social services or a paediatrician.
Ask patients about sensorineural deafness and first degree family history of chronic kidney disease as several rare familial haematuria syndromes exist, notably Alport syndrome, with several inheritance patterns. Male children with X-linked Alport syndrome have non-visible haematuria, with proteinuria in childhood progressing to end-stage kidney failure in their 20s. Early detection and treatment with angiotensin-converting enzyme (ACE) inhibitors can slow disease progression. About 15% of female carriers (all have non-visible haematuria) progress to end-stage kidney failure by the age of 60 years.17 Genomic haematuria panels are available for these high risk groups and are undertaken by genetic or tertiary care services.
Ask about travel or migration history. Children who have spent time in sub-Saharan Africa or South East Asia may be infected with Schistosoma haematobium, with haematuria (visible or non-visible) often the only symptom.
Perform a focused abdominal examination for a kidney mass. An abdominal mass is palpable in 80% children with a Wilms’s tumour. This most commonly presents in children aged 2-3 years and up to the age of 8 years.18
What investigations can be requested in primary care?
Initial investigations depend on whether the likely origin is from the kidney (nephritis) or urinary tract (table 1).
Confirm haematuria with urine dipstick testing.
In well infants, discoloration of nappy material may mimic blood, so confirm this by collecting a clean catch sample.
Check early morning urine albumin to creatinine ratio (ACR) if dipstick testing shows proteinuria; do baseline blood tests (urea, creatinine, electrolytes) and calculate glomerular filtration rate (GFR) (table 1).
In practice, renal ultrasound is commonly used in the assessment of visible haematuria, but not all studies or guidelines support its usefulness in this context.13
Genetic testing is available only in secondary or tertiary care for specific indications; refer if child has high tone sensorineural hearing loss or if there is a first degree relative with haematuria or unexplained chronic kidney disease.
What are the differential diagnoses?
Table 2 presents differential diagnoses for visible and non-visible haematuria. Causes of non-visible haematuria are similar to those for visible haematuria but with much lower yield from investigations. In two retrospective cohort studies of US children’s hospitals with 700 children investigated,12 fewer than 1% with non-visible haematuria had actionable findings.21
Differential diagnosis of haematuria (visible and non-visible)
How should I manage a paediatric patient with haematuria?
Visible haematuria
Refer all patients with visible haematuria to a general paediatrician. Most children with normal initial investigations will not have further episodes of visible haematuria. Other indications for referral include:
Persistent proteinuria, defined as ACR >3 mg/mmol on a morning urine sample
Recurrent visible haematuria without a cause
Any abnormal results from investigations
Patients with suspected infection with Schistosoma haematobium based on travel or migration history.
Symptomatic patients (high blood pressure, significant proteinuria, passing blood clots, persistent significant discomfort not improving with treatment for urinary tract infections) should be discussed with a secondary care paediatrician for a more urgent review.
Non-visible haematuria
If there is non-visible haematuria and clinical features of urinary tract infection, send a urine culture and treat as a urinary tract infection as per the NICE guideline on urinary tract infection in children.8 A clinically well child with persistent, isolated non-visible haematuria and with normal blood pressure and blood and urine tests can be referred to an outpatient clinic with appropriate safety-netting and primary care monitoring
Despite very low yield from investigations, no consensus guideline has been produced for non-visible haematuria. Non-visible haematuria is most commonly intermittent in otherwise healthy and asymptomatic children. Most cases are idiopathic and settle within six months.
Figure 1 presents a suggested flowchart for management of asymptomatic incidental non-visible haematuria based on published practices from several review articles.19202223
Suggested flowchart for management of asymptomatic, incidental non-visible haematuria
In the UK paediatric nephrology and urology are organised in regional networks via local paediatricians as first access point. Specialist imaging, cystoscopy, or kidney biopsies may be required, as well as a multidisciplinary assessment of the child to reach a diagnosis. In retrospective cohort studies, paediatric kidney biopsy in cases of non-visible haematuria showed either early glomerulonephritis or basement membrane abnormalities, but results did not change management.24
Informing patients and parents, shared decision making
The causes of haematuria in children are generally benign and reversible, and patients and parents can often be reassured accordingly. In visible haematuria, initial investigations in primary care (if practical) such as blood pressure, urine and blood tests, and ultrasound scan will probably point to the underlying cause, and a referral is then made to a paediatrician for follow-up. In cases of non-visible haematuria that is intermittent and short lasting (<6 months), although the underlying cause often remains elusive, patients and parents can be reassured that it is unlikely to be harmful. If intermittent non-visible haematuria persists beyond six months or keeps recurring then a referral to a paediatrician should be made, and urine, renal function tests, and blood pressure be monitored long term to detect early signs of renal impairment. Patients and parents should be provided with safety-netting advice such as to seek medical assessment should haematuria worsen, change from non-visible haematuria to visible haematuria, or associated symptoms such as dysuria or passing of blood clots develop.
How patients were involved in the creation of this article
Parents of children with non-visible haematuria were asked in clinic about their diagnostic journey. There was a spectrum of reactions, from being unfazed to continuing concern at the diagnostic uncertainty despite normal blood and imaging tests. All expressed the difficulty of hearing different information from different healthcare professionals. This feedback helped the article to demonstrate the low yield of investigations, emphasised the need for clear communication with patients and parents, and empowering patients and parents by offering choices about the extent of investigations.
Education into practice
What causes do you think about when assessing children with haematuria?
Do you routinely investigate children with haematuria?
When do you refer children with haematuria?
How this article was created
This article is the result of a collaboration between a general practitioner, paediatric urological surgeon, paediatric nephrologist, and general paediatrician and infectious diseases specialist, supplemented by Medline and Cochrane Library searches by each of the collaborators using the search terms “haematuria” and “hematuria” in combination with “cause”, “diagnosis”, and “treatment” and limited to the paediatric age group.
Footnotes
Contributors: All authors contributed equally to the conception and design; drafting of the paper, figure, and tables; and are guarantors. All authors approved of the final version, and all accept responsibility for all aspects of this work.
Competing interests: We have read and understood the BMJ policy on declaration of interests and have no relevant interests to declare.
References
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