[Liddle's syndrome: late diagnosis of a rare cause of arterial hypertension].

Objective: The aim of this article is to highlight the importance of a rare disease that causes severe arterial hypertension in children. It is important to advise pediatricians to measure arterial pressure in children in order to avoid late diagnosis and renal insufficiency.

Description: We report a case of a 13-year-old patient that presented typical clinical and laboratorial features of Liddle's syndrome. The diagnosis was established based on the clinical picture associated with the presence of chronic hypokalemia, increase of urinary potassium excretion with sodium retention and reduction of renin plasma activity, and circulating levels of angiotensin II and aldosterone. In a spite of the initial therapeutic response to triamterene, the patient developed progressive renal failure due to the delay in the diagnosis and the poorly controlled hypertension.

Comments: Liddle's syndrome consists of a form of pseudoaldosteronism characterized by arterial hypertension, hypokalemia, metabolic alkalosis and failure to thrive. Some aspects regarding physiopathology, diagnosis and treatment are discussed.