From the Guidelines
For abnormal hair growth in a girl, the most critical hormones to check are total testosterone (TT) and free testosterone (FT), as they are the first-line laboratory tests recommended for assessing biochemical hyperandrogenism in the diagnosis of polycystic ovary syndrome (PCOS) 1. These tests are crucial for identifying the underlying cause of hirsutism, which is often related to conditions like PCOS, congenital adrenal hyperplasia, or other androgen-producing disorders. The timing of these tests is important, and they should ideally be performed in the early morning and during the follicular phase of the menstrual cycle (days 3-8) for accurate results. Some key points to consider when evaluating abnormal hair growth in girls include:
- The use of liquid chromatography with tandem mass spectrometry (LC-MS/MS) for androgen measurement, given its high accuracy 1.
- The consideration of androstenedione (A4) and dehydroepiandrosterone sulfate (DHEAS) if TT or FT are not elevated, noting their poorer specificity 1.
- The importance of early diagnosis, as these hormonal imbalances can lead to long-term health issues, including metabolic disorders and fertility problems if left untreated. Additional tests may include thyroid function tests, insulin levels, and a pelvic ultrasound to evaluate for ovarian abnormalities. The pattern of hormone abnormalities helps determine the appropriate treatment approach, which may include lifestyle modifications, oral contraceptives, anti-androgens, or specific treatments for identified underlying conditions. It is essential to follow the recommendations of the 2023 International PCOS Guidelines, which suggest using TT, FT, and free androgen index (FAI) as first-line laboratory tests to assess biochemical hyperandrogenism in the diagnosis of PCOS 1.
From the Research
Hormones to be Checked for Abnormal Hair Growth in Girls
The following hormones should be checked for abnormal hair growth in girls:
- Androgen levels, including testosterone and dihydrotestosterone (DHT) 2, 3, 4
- Dehydroepiandrosterone sulfate (DHEA-S) 2, 4, 5
- 17-hydroxyprogesterone (17-OH Prog) 2, 5
- Estradiol, as it can alter the hair follicle growth and cycle 4
- Progesterone, as it can decrease the conversion of testosterone into DHT 4
- Prolactin (PRL), as it has been detected in human scalp skin and may influence hair growth 4
When to Check Hormone Levels
Hormone levels should be checked in girls with:
- An abnormal hirsutism score based on the Ferriman-Gallwey scoring system 2, 3
- Rapid onset of hirsutism over a few months or signs of virilization, as they are at high risk of having an androgen-secreting tumor 2
- Patient-important hirsutism despite cosmetic measures, as pharmacological therapy may be necessary 3