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| Hypertension | ||
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Seth L. Schulman
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Database Differential Diagnosis Data Gathering Physical Examination Laboratory Aids Therapy Follow-Up Common Questions and Answers Bibliography |
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DEFINITION
Hypertension is average systolic and/or diastolic blood pressures above the 95th percentile for age and gender as defined by the Second Task Force on Blood Pressure Control in Children. References also include norms based on the patient’s height percentile. The final determination should be based on at least three measurements obtained on separate occasions. The significance of this definition with regard to morbidity and mortality is unclear.
PATHOPHYSIOLOGY
Hypertension is either primary (essential) or secondary. Secondary causes, with examples, include:
GENETICS
Primary hypertension is more likely to develop in individuals when there is a strong family history. The genetics of secondary causes depend on the condition (e.g., polycystic kidney disease: autosomal dominant, autosomal recessive; neurofibromatosis: autosomal dominant; glucocorticoid-remediable aldosteronism: autosomal dominant).
EPIDEMIOLOGY
Primary hypertension is the most common cause of hypertension in adolescents and adults. Various rates of hypertension in children have been reported, from 1.2% to 13%, but less than 1% appear to require medication. African American adults have a greater incidence of hypertension. Differences in children, however, are not seen until after age 12. Tracking (i.e., determining the risk of hypertension based on earlier blood pressure measurements) is not reliable in children.
COMPLICATIONS
PROGNOSIS
The patient’s prognosis depends on the underlying cause of the hypertension. It is excellent if the blood pressure is well controlled.
| DIFFERENTIAL DIAGNOSIS | ||
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The initial objective after diagnosing hypertension in children is distinguishing primary from secondary causes. Generally, the younger the child and more elevated the blood pressure measurements, the more likely the cause of hypertension is secondary.
| DATA GATHERING | ||
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HISTORY
Question: Is there a family history of hypertension?
Significance: Hypertension may be familial.
Question: Do you have symptoms of headache or blurry vision?
Significance: These are signes of increased intracranial pressure.
Question: Do you have chest pain?
Significance: This may indicate hypertensive heart disease or decreased coronary blood flow.
Question: Do you have epistaxis, weight gain or loss?
Significance: These are other signs of hypertension.
Question: Do you have flushing?
Significance: Flushing may be a sign of pheochromocytoma.
Question: Do you have a history of urinary tract infections?
Significance: Infections can be associated with reflux nephropathy and hypertension.
Special Questions
| PHYSICAL EXAMINATION | ||
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| LABORATORY AIDS | ||
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TESTS
The laboratory evaluation for hypertension should proceed in a stepwise fashion.
| THERAPY | ||
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| FOLLOW-UP | ||
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The reduction of blood pressure with medication should be gradual to avoid side effects. The medications themselves cause adverse effects, such as exercise intolerance (b-blockers), headaches (vasodilators), renal insufficiency (ACE inhibitors), and hypokalemia (diuretics). Certain classes of medication should be avoided in patients with specific conditions, such as asthma and diabetes (b-blockers) and renal artery stenosis (ACE inhibitors).
PITFALLS
| COMMON QUESTIONS AND ANSWERS | ||
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Q: How does licorice cause hypertension?
A: British licorice contains glycyrrhizinic acid, a mineralocorticoid-like substance that causes sodium retention, potassium wasting, and hypertension. This substance is not found in most commercially available licorice in the United States.
Q: What percentage of children have renovascular causes for their hypertension?
A: Studies looking at the etiology of hypertension indicate that 10% to 24% of children may have a renovascular cause. Children under 5 years of age are four times more likely to have renal artery stenosis than are adolescents.
Q: What are the indications for invasive studies such as angiography?
A: This decision should be individualized and based on the severity of the hypertension, response to medication, the clinical presentation (e.g., neurofibromatosis), and results of other studies. In general, young children and all children with severe, unexplained hypertension should be completely evaluated.
Q: Can adolescents with elevated blood pressure compete in sports?
A: Adolescents with hypertension should be encouraged to participate in athletics if their blood pressures are well controlled. The use of stress testing in this population is controversial.
ICD-9-CM 401.9 (unspecified)
| BIBLIOGRAPHY | ||
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Daniels SR. Hypertension in childhood. Pediatr Rev 1997; 18:331.
Fivush B, Neu A, Firth S. Acute hypertensive crises in children: emergencies and urgencies. Curr Opin Pediatr 1997; 9:233–236.
Rocchini AP, ed. Childhood hypertension. Pediatr Clin North Am 1993; 40:1–212.
Rosner B, Prineas RJ, Loggie JMH, Daniels SR. Blood pressure nomograms for children and adolescents, by height, sex, and age, in the United States. J Pediatr 1993; 123:871–876.
Sinaiko AR. Hypertension in children. N Engl J Med 1996; 335:1968–1973.
Task Force on Blood Pressure Control in Children. Report of the Second Task Force on Blood Pressure Control in Children. Pediatrics 1987; 79:1–25.
Copyright © 2000 Lippincott Williams & Wilkins
M. William Schwartz, Louis M. Bell, Jr., Peter M. Bingham, Esther K. Chung, David F. Friedman and Andrew E. Mulberg, The 5 Minute Pediatric Consult