Paediatrics: Hypertension - causes and features

Hypertension: causes and features

Causes of hypertension

Primary (essential) hypertension

This is a diagnosis of exclusion. High body mass index, excessive salt intake, lack of exercise, and family history may be underlying predisposing factors

Secondary hypertension

• Renal (commonest cause in-hospital referral practice):

o chronic renal parenchymal disease (reflux/scarring)

o polycystic kidney disease

o obstructive uropathy

o acute nephritis

o chronic renal failure

• Vascular:

o umbilical arterial/venous catheters

o renal artery stenosis

o renal vein thrombosis

o coarctation of the aorta

o vasculitis

• Endocrine:

o congenital adrenal hyperplasia

o hyperthyroidism

o increased steroids (iatrogenic or endogenous)

o phaeochromocytoma (BP intermittently raised)

o hyperaldosteronism

• Trauma
• Neurological:

o 2° to pain

o raised intracranial hypertension

• Tumours:

o neuroblastoma

o Wilms

• Medication:

o steroids

o aminophylline/caffeine

o oral contraceptive pill

o erythropoietin

o calcineurin inhibitors; decongestants

o amphetamines; cocaine

• Others:

      bronchopulmonary dysplasia

      ECMO

      ‘white-coat’ hypertension

Clinical features

Most are asymptomatic.

Infants

• Vomiting.
• Failure to thrive (rare).
• Congestive cardiac failure/respiratory distress (in newborns).

Children

• Headache/nausea and vomiting.
• Visual symptoms.
• Irritable/tired.
• Bell’s palsy.
• Epistaxis.
• Growth failure.
• Fits.
• Altered consciousness.

Examination

• Check fundi.
•  Feel abdomen for abdominal masses.
• Listen for renal bruits.
• Feel femoral pulses and compare to radial/brachial pulses (to exclude
• coarctation) and check BP in all 4 limbs.
• Examination of the heart.

Investigations

As the cause is more likely with severe hypertension. Treatment and investigations may need to proceed together.

• Urine:
•  urinalysis, microscopy, and culture;
• vanillylmandelic acid (VMA): creatinine ratio;
• steroid profile and toxicology.
• Blood tests:

     - FBC;

      - U&E and creatinine;

     -  Bicarbonate, calcium, phosphate, albumin;

      - Plasma renin and aldosterone.

• CXR and ECG.
• ECG.
• The US of urinary tract + Doppler if renal artery stenosis suspected.
• Further imaging will depend upon suspected cause and ultrasound
• findings, e.g. DMSA, CT scan, arteriogram.
• Specialized tests, e.g. for phaeochromocytoma.