endo-hirsutism-screen-nccah-high-risk

name	endo-hirsutism-screen-nccah-high-risk
description	This skill screens high‑risk patients for nonclassic congenital adrenal hyperplasia (NCCAH) by measuring 17‑OHP even when total and free testosterone are normal. Use when a clinician says, "She has a family history of CAH; should we still screen despite normal androgens?" or notes positive family history or high‑risk ethnic group.

Screen high‑risk patients for NCCAH regardless of testosterone

STEP 1 — Gather Information

Collect hirsutism score (Ferriman–Gallwey), menstrual pattern, signs of hyperandrogenism (oligomenorrhea, infertility, acne, alopecia), family history of CAH, and ethnic background (e.g., Ashkenazi Jewish, Hispanic, Mediterranean, Middle Eastern, South Asian). Decide if patient is hyperandrogenemic or high‑risk for NCCAH.

STEP 2 — Rule In / Rule Out

If the patient has either an abnormal hirsutism score/clinical hyperandrogenism OR a positive family history of CAH or belongs to a high‑risk ethnic group, proceed to measure 17‑OHP; otherwise, do not screen for NCCAH and evaluate other causes of hirsutism.

STEP 3 — Classify or Stratify

For patients with regular menstrual cycles, obtain an early‑morning (8 am) serum 17‑OHP during the follicular phase (days 3‑5); for those with amenorrhea or infrequent menses, obtain a random‑day 17‑OHP level.

STEP 4 — Decide

Interpret the 17‑OHP result: <170 ng/dL (5.15 nmol/L) makes NCCAH unlikely; 170‑200 ng/dL (5.15‑6.0 nmol/L) warrants an ACTH stimulation test; ≥1000 ng/dL (30 nmol/L) basal or post‑stimulation supports a diagnosis of NCCAH.

Clinical Guardrails / Mimics / Pitfalls

Do not exclude NCCAH based solely on normal total or free testosterone in high‑risk patients; avoid measuring 17‑OHP in the luteal phase without adjustment; remember that glucocorticoid therapy can suppress 17‑OHP and mask NCCAH; consider other causes of elevated 17‑OHP (e.g., stress, ovarian tumors, 11‑β‑hydroxylase deficiency) and confirm with cosyntropin stimulation or genetic testing when indicated.

Concrete Clinical Example

A 28‑year‑old woman with mild hirsutism (FG score 9), regular menses, and a sister diagnosed with classic CAH presents for evaluation. Her total and free testosterone are normal. Because she has a positive family history, step 2 indicates screening. She undergoes follicular‑phase 17‑OHP, which returns 185 ng/dL. This intermediate value prompts an ACTH stimulation test, revealing a peak 17‑OHP of 1250 ng/dL, confirming NCCAH. She is started on low‑dose glucocorticoid therapy for adrenal suppression.

Source: Evaluation and Treatment of Hirsutism in Premenopausal Women: An Endocrine Society Clinical Practice Guideline, Endocrine Society, 2018, https://doi.org/10.1210/jc.2018-00241

TODO: consider adding scripts/calc.py for the endo-hirsutism-screen-nccah-high-risk calculator