Evaluation and Management of Elevated DHEA-S in Adolescent Hirsutism
For an adolescent with elevated DHEA-S and hirsutism, first measure total testosterone (TT) and free testosterone (FT) using LC-MS/MS, as these are the primary androgens for diagnosing hyperandrogenism; DHEA-S elevation alone has poor specificity and should prompt evaluation for late-onset congenital adrenal hyperplasia (CAH) with an ACTH stimulation test. 1
Initial Diagnostic Approach
First-Line Androgen Testing
- Measure TT and FT as primary tests for biochemical hyperandrogenism, preferably using LC-MS/MS methodology for accuracy 1
- Calculate free testosterone using equilibrium dialysis, ammonium sulfate precipitation, or free androgen index (FAI) 1
- DHEA-S has poorer specificity than TT/FT for diagnosing hyperandrogenism and should be considered a secondary test 1
When DHEA-S is Markedly Elevated
- If DHEA-S >600 μg/dL (>16.3 μmol/L), consider androgen-secreting adrenal adenoma and obtain adrenal imaging 2
- For moderately elevated DHEA-S with hirsutism, perform ACTH stimulation test to evaluate for late-onset CAH 3
ACTH Stimulation Testing
Indications and Interpretation
- 61% of hirsute women have subtle defects in adrenal steroidogenesis revealed by ACTH stimulation 3
- Measure baseline and ACTH-stimulated levels of: 17-hydroxypregnenolone (Δ5-17P), 17-hydroxyprogesterone (17-OHP), DHEA, androstenedione, and cortisol 3
- Basal DHEA-S levels do not predict ACTH response—13 patients with defective steroidogenesis had normal baseline DHEA-S 3
Specific Enzyme Deficiencies to Identify
21-Hydroxylase Deficiency (Nonclassical CAH):
- ACTH-stimulated 17-OHP >5,000 ng/dL with low Δ5-17P/17-OHP ratio (<0.4) 4
3β-Hydroxysteroid Dehydrogenase Deficiency:
- ACTH-stimulated Δ5-17P >2,000 ng/dL and DHEA >2,500 ng/dL 4
- Elevated Δ5-17P/17-OHP ratio (>11) and DHEA/androstenedione ratio (>7.5) 4
- Morning DHEA-S and Δ5-17P show diurnal variation and suppress with dexamethasone 4
Management Strategy
Pharmacological Treatment
First-Line Therapy:
- Recommend oral combined estrogen-progestin contraceptives as initial pharmacological treatment for most adolescents with hirsutism 5
- Add an antiandrogen after 6 months if response is suboptimal 5
- Never use antiandrogen monotherapy without adequate contraception due to teratogenicity risk 5
For Adrenal-Source Hyperandrogenism:
- Consider bedtime dexamethasone (0.25-0.5 mg) only if free testosterone can be maintained <15 pg/mL without side effects 6
- Oral contraceptives produce significantly greater testosterone reduction than dexamethasone and improve hirsutism more effectively 6
- Dexamethasone alone decreased hirsutism in only 4/14 patients, while oral contraceptives improved all patients 6
Direct Hair Removal Methods
- Add laser/photoepilation for additional cosmetic benefit if pharmacological therapy alone is insufficient 5
- Diode laser is more effective in patients with normal androgen levels than those with elevated DHEA-S/DHT 7
Important Clinical Pitfalls
Avoid These Common Errors
- Do not rely on basal DHEA-S alone—it correlates poorly with adrenal enzyme defects and may be normal despite significant steroidogenic abnormalities 3
- Do not assume normal testosterone excludes hyperandrogenism in hirsute patients—SHBG may be reduced with obesity or metabolic syndrome, masking elevated free testosterone 2
- Do not use insulin-lowering drugs for hirsutism treatment 5
- Do not perform adrenal biopsy routinely for adrenal masses 1
When to Suspect Adrenal Tumor
- DHEA-S >600 μg/dL warrants adrenal imaging with non-contrast CT 1, 2
- In suspected adrenocortical carcinoma with virilization, test comprehensive androgen panel including DHEA-S, testosterone, androstenedione, and 17-OH progesterone 1