From the Guidelines
The diagnostic workup for an adult with suspected Congenital Adrenal Hyperplasia (CAH) should begin with measurement of morning serum 17-hydroxyprogesterone (17-OHP) levels, which is the primary screening test, as indicated by the most recent guidelines and studies, although not directly mentioned in 1. When evaluating an adult for CAH, it is essential to consider the clinical presentation, including signs of hyperandrogenism, such as hirsutism, acne, and male pattern baldness in females, as well as menstrual irregularities and infertility.
- Key laboratory tests include:
- Morning serum 17-OHP levels
- ACTH stimulation test to confirm the diagnosis
- Serum electrolytes to assess for salt wasting
- Plasma renin activity
- Serum androstenedione, testosterone, and DHEAS to evaluate androgen excess
- Genetic testing for mutations in the CYP21A2 gene can confirm the diagnosis and help determine the specific CAH variant, although this is not directly addressed in 1.
- Adrenal imaging with CT or MRI may be warranted in some cases to rule out adrenal tumors or hyperplasia, but this is not explicitly mentioned in the provided evidence. It is crucial to note that while 1 discusses the role of androgens in acne pathogenesis and the indications for endocrinologic evaluation, it does not directly address the diagnostic workup for CAH. However, the principles of evaluating androgen excess and hyperandrogenism can be applied to the diagnosis of CAH.
- Clinical assessment should include evaluation of symptoms such as hirsutism, menstrual irregularities in women, infertility, and hypertension, as these manifestations vary depending on the enzyme deficiency and severity of the condition. Given the complexity of hormonal testing and interpretation, as mentioned in 1, a comprehensive approach is necessary for accurate diagnosis and management of CAH.
From the Research
Diagnostic Workup for Adult CAH
The diagnostic workup for an adult with suspected Congenital Adrenal Hyperplasia (CAH) involves several steps, including:
- Clinical evaluation: assessing symptoms such as hirsutism, irregular menses, and infertility 2, 3
- Laboratory tests: measuring serum cortisol, 17-hydroxyprogesterone, and androstenedione levels 4, 5
- ACTH stimulation test: to evaluate the response of the adrenal glands to adrenocorticotropic hormone (ACTH) 6
- Genetic testing: to identify mutations in the CYP21A2 gene, which is responsible for 21-hydroxylase deficiency 6
- 24-hour urinary steroid profile (USP) analysis: to assess the production of various steroids and confirm the diagnosis of CAH 6
Laboratory Tests
Laboratory tests play a crucial role in the diagnosis of CAH. The following tests are commonly used:
- Serum 17-hydroxyprogesterone: elevated levels are indicative of 21-hydroxylase deficiency 4, 5
- Serum androstenedione: elevated levels are associated with androgen excess 4
- Serum cortisol: low levels may indicate adrenal insufficiency 4, 5
Interpretation of Test Results
The interpretation of test results is critical in the diagnosis of CAH. For example:
- A basal or post-ACTH stimulated 17-hydroxyprogesterone level ≥30 nmol/l may indicate NCCAH, but can also lead to false-positive diagnosis 6
- The diagnosis of NCCAH should be confirmed by USP and/or genetic testing 6
Monitoring and Management
Once the diagnosis of CAH is confirmed, regular monitoring and management are essential to prevent long-term complications, such as: