A 7-year-old girl had growth of pubic hair for the past 6 months. The hair was initially limited to the labia majora and then extended gradually into the pubic area. She grew 8 cm (3.1 in) in the past year. Her health history was unremarkable; she was not taking any medications. On examination, her weight was 35 kg (77.2 lb); height, 125 cm (49.2 in). She did not have breast development, axillary hair, acne, or clitoral enlargement.
Premature or precocious adrenarche refers to an earlier than normal secretion of adrenal androgens that results in isolated development of pubic hair (pubarche) before age 8 years in girls and 9 years in boys, without the appearance of other signs of sexual maturation. It affects about 0.8% of white girls aged 7 to 7.9 years. The condition is more common in African American children. The female to male ratio is approximately 10:1.
Premature adrenarche is secondary to an early isolated maturation of the zona reticularis, with increased adrenal androgen secretion for chronological age but with normal glucocorticoid levels. Another suggested mechanism is increased sensitivity of the sexual hair follicles to androgens, because in some patients, premature pubarche is associated with normal androgen levels.
Precocious puberty can be differentiated from premature adrenarche by the concomitant appearance of pubic hair with breast development in girls and with testicular enlargement in boys. Other differential diagnoses include virilization caused by congenital adrenal hyperplasia and an adrenocortical or gonadal tumor. In premature adrenarche, serum concentrations of dehydroepiandrosterone, dehydroepiandrosterone sulfate (DHEAS), androstenedione, and testosterone and urinary 17-ketosteroids are usually increased for chronological age and in the range of those found in early puberty. The bone age is usually within 2 standard deviations of the chronological age. Moderately elevated levels of serum androgen other than DHEAS, bone age advancement, or signs of atypical premature pubarche (such as cystic acne or symptoms of systemic virilization) indicate the need for a corticotropin test to rule out late-onset congenital adrenal hyperplasia. Marked elevation of serum androgen levels and advanced bone age suggest the possibility of an adrenocortical or gonadal tumor.
Education and reassurance of the patient and family along with psychological/emotional support are essential to clinical management of premature adrenarche. Continued observation and periodic reevaluation are necessary because premature adrenarche might be the first sign of precocious puberty. Premature adrenarche in girls is associated with a higher incidence of polycystic ovary syndrome later in life. In some girls, premature adrenarche may be a forerunner of polycystic ovary syndrome or syndrome X (obesity, hypertension, insulin resistance, type 2 diabetes mellitus, and dyslipidemia). Affected patients are at increased risk for early atherosclerotic cardiovascular disease. In contrast, premature adrenarche in boys is not associated with an increased incidence of endocrine or metabolic abnormalities.
Girls with higher body mass index warrant particularly close follow-up. Early identification of these patients can allow for earlier treatment of the associated conditions with a reduction in risk of early cardiovascular disease.
FOR MORE INFORMATION:
• Andiran N, Yordam N, Kirazli S. Global fibrinolytic capacity is decreased in girls with premature adrenarche: a new pathological finding? J Pediatr Endocrinol Metab. 2005;18:1373-1381.
• Leung AK, Robson WL. Premature adrenarche. J Pediatr Health Care. 2008; 22:230-233.
• Saenger P, DiMartino-Nardi J. Premature adrenarche. J Endocrinol Invest. 2001;24:724-733.