From the Guidelines
For a 6-year-old with excessive hair growth (hirsutism) in the back, pubic area, and armpits over the last 6 months, I recommend ordering comprehensive hormonal blood work to evaluate for precocious puberty or adrenal disorders. The initial panel should include serum testosterone, dehydroepiandrosterone sulfate (DHEAS), 17-hydroxyprogesterone, androstenedione, luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol, thyroid function tests (TSH, free T4), and a complete metabolic panel. Morning cortisol levels and ACTH should also be measured to assess adrenal function, as suggested by guidelines for endocrinologic evaluation in cases of hyperandrogenism 1. These tests will help identify the source of excess androgens, which are likely causing the abnormal hair growth. The most common causes in this age group include congenital adrenal hyperplasia, adrenal or ovarian tumors, or early puberty. The pattern of hormone elevation will guide further diagnostic steps, which might include imaging studies of the adrenal glands or pituitary. This workup is urgent as premature development of secondary sexual characteristics in a 6-year-old requires prompt evaluation and management to address both the underlying cause and potential psychological impacts. Key points to consider in the diagnostic workup include:
- Clinical features of hyperandrogenism, such as acne, early-onset body odor, axillary or pubic hair, accelerated growth, advanced bone age, and genital maturation 1
- The role of androgens in acne pathogenesis and the indication for endocrinologic evaluation in certain cases 1
- The importance of growth charts and a hand film for bone age as good screening tools before specific hormonal testing 1
- The differential diagnosis of polycystic ovarian syndrome (PCOS) and nonclassical congenital adrenal hyperplasia, among others 1
From the Research
Blood Work for Excessive Hair Growth in a 6-year-old
To determine the cause of excessive hair growth in a 6-year-old, several blood tests can be ordered. The following are potential tests:
- 17-hydroxyprogesterone level: This test is used to diagnose Congenital Adrenal Hyperplasia (CAH), a condition characterized by androgen excess secondary to impaired steroidogenesis in the adrenal glands 2, 3, 4.
- Androgen levels: Elevated androgen levels can indicate an underlying condition such as CAH or functional ovarian hyperandrogenism 5, 4.
- Adrenocorticotropic hormone (ACTH) level: This test can help diagnose adrenal insufficiency or Cushing's syndrome, which can also cause excessive hair growth 4.
- Cortisol level: This test can help diagnose Cushing's syndrome or adrenal insufficiency 4.
- Thyroid function tests: Although less likely, thyroid disorders can also cause changes in hair growth, so thyroid function tests may be ordered to rule out this possibility.
Rationale for Blood Work
The rationale for ordering these blood tests is to rule out underlying conditions that may be causing the excessive hair growth. CAH, in particular, is a condition that can cause premature adrenarche, growth acceleration, hirsutism, and irregular menses 2. By ordering these blood tests, healthcare providers can determine if the child has an underlying hormonal imbalance that needs to be addressed.
Additional Considerations
It is essential to note that excessive hair growth in children can be caused by various factors, including genetic conditions, hormonal imbalances, and certain medications 5, 6. A thorough medical history and physical examination are necessary to determine the underlying cause of the excessive hair growth. If the blood tests reveal an underlying condition, treatment can be initiated to address the condition and manage the symptoms.