Introduction
Hypertension in children is becoming increasingly recognized, especially with rising obesity rates. Unlike adults, pediatric hypertension is often secondary to an underlying cause, making early identification crucial to prevent long-term complications.
Causes of Hypertension in Pediatrics
Pediatric hypertension is classified into primary (essential) hypertension and secondary hypertension.
1. Primary (Essential) Hypertension
- More common in adolescents
- Strong genetic predisposition
- Associated with obesity, metabolic syndrome, and sedentary lifestyle
2. Secondary Hypertension
More common in younger children and often due to an underlying medical condition.
A. Renal Causes (Most Common)
- Renal parenchymal disease (glomerulonephritis, reflux nephropathy, polycystic kidney disease)
- Renovascular disease (renal artery stenosis, fibromuscular dysplasia)
B. Endocrine Causes
- Cushing’s syndrome
- Congenital adrenal hyperplasia (CAH)
- Pheochromocytoma
- Hyperthyroidism or hypothyroidism
- Primary hyperaldosteronism (Conn’s syndrome)
C. Cardiovascular Causes
- Coarctation of the aorta
- Takayasu arteritis
D. Neurological Causes
- Increased intracranial pressure (brain tumors, hydrocephalus)
E. Iatrogenic Causes
- Medications: Steroids, NSAIDs, decongestants, oral contraceptives, chemotherapy drugs
Approach to a Child with Hypertension
Step 1: Confirm Hypertension
- Blood Pressure Measurement:
- Measure in a calm environment
- Use the correct cuff size (bladder covering 80–100% of arm circumference)
- Take ≥3 separate readings on different occasions
- Check blood pressure in all four limbs if coarctation is suspected
- BP Classification (Based on Age, Gender, and Height Percentile):
- Normal: <90th percentile
- Elevated BP: 90th–95th percentile
- Hypertension: ≥95th percentile
- Stage 1 HTN: 95th–99th percentile + 5 mmHg
- Stage 2 HTN: >99th percentile + 5 mmHg
Step 2: History and Physical Examination
History:
- Family history of hypertension, renal disease, endocrine disorders
- Birth history (prematurity, NICU stay, umbilical catheterization)
- Dietary history (salt intake, caffeine consumption)
- Medication use (steroids, OCPs, stimulants)
- Symptoms suggesting secondary causes:
- Headache, sweating, palpitations → Pheochromocytoma
- Polyuria, muscle weakness → Hyperaldosteronism
- Fatigue, weight gain → Hypothyroidism
Physical Examination:
- Growth parameters: Obesity (Metabolic syndrome)
- Blood pressure in all four limbs (Coarctation of aorta)
- Fundoscopy (Hypertensive retinopathy)
- Abdominal bruit (Renovascular disease)
- Skin findings:
- Café-au-lait spots → Neurofibromatosis (Renal artery stenosis)
- Striae, buffalo hump → Cushing’s syndrome
Step 3: Initial Investigations
- Basic Workup:
- CBC, Urinalysis (Hematuria, proteinuria)
- Serum electrolytes, BUN, creatinine (Renal function)
- Lipid profile, fasting glucose (Metabolic syndrome)
- Thyroid function tests
- Target Organ Damage Assessment:
- Echocardiography (Left ventricular hypertrophy)
- Fundoscopy (Retinopathy)
- Further Workup for Secondary Causes (if indicated):
- Renal ultrasound (Renal disease, Wilms tumor)
- Renal Doppler (Renovascular disease)
- Plasma renin and aldosterone levels (Hyperaldosteronism)
- 24-hour urine metanephrines (Pheochromocytoma)
- MRI angiography (Coarctation of aorta, Takayasu arteritis)
Management Approach
1. Lifestyle Modifications (First-line for Primary HTN and Adjunct for Secondary HTN)
- Weight loss and exercise (≥60 min/day)
- Dietary changes:
- Low salt, high potassium (DASH diet)
- Avoid processed food, caffeine, sugary drinks
- Screen for obstructive sleep apnea
2. Pharmacological Treatment (If BP Remains High Despite Lifestyle Changes or Secondary HTN is Present)
First-line Antihypertensives:
- ACE inhibitors (Enalapril, Lisinopril) – First choice in chronic kidney disease
- ARBs (Losartan, Valsartan) – Alternative to ACE inhibitors
- Calcium channel blockers (Amlodipine, Nifedipine) – Good for coarctation or primary hypertension
- Beta-blockers (Propranolol, Atenolol) – For hyperthyroidism, migraine, or anxiety-related hypertension
- Diuretics (Hydrochlorothiazide, Furosemide) – Useful in volume overload states
3. Treat Underlying Cause (For Secondary HTN)
- Coarctation of aorta → Surgical repair
- Renovascular disease → Angioplasty or surgery
- Endocrine disorders → Specific hormone therapy
Conclusion
Hypertension in children requires a systematic approach to identify the cause, assess target organ damage, and initiate appropriate treatment. Primary hypertension is more common in adolescents, while secondary hypertension is more likely in younger children and warrants an extensive workup. Early detection and management are crucial to prevent long-term complications.
