Late-onset Congenital Adrenal Hyperplasia

When considering a diagnosis of polycystic ovary syndrome (PCOS), it is typical for a doctor to consider late-onset congenital adrenal hyperplasia (CAH), too. This is because these two diseases often present the same symptoms.

birth control pills
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Late-onset Congenital Adrenal Hyperplasia

Congenital adrenal hyperplasia is an inherited group of diseases in which a key enzyme is missing from the body. Genetic defects present at the time of birth (congenital) affect several enzymes that are needed to produce vital adrenal cortex hormones.

Almost 95 percent of CAH cases are caused by a lack of the enzyme 21-hydroxylase. The body cannot make adequate amounts of two key adrenal steroid hormones—cortisol and aldosterone—when enzyme 21-hydroxylase is missing or functioning at a low level.

This throws off the delicate balance of hormones, preventing the proper synthesis of aldosterone and cortisol, and the adrenal cortex starts to make androgens (male steroid hormones), leading to masculine traits in females. In this classical form of CAH, salt balance can also be drastically altered, leading to electrolyte imbalances, dehydration, and cardiac rhythm changes.

While many patients are diagnosed shortly after birth, there is a type of this disease that develops later in life, usually in adolescence or early adulthood—it's called non-classical or late-onset CAH.

These people are missing only some of the enzymes that are necessary for cortisol production. Aldosterone production is not affected, so this form of the disease is less severe than the congenital form and shows symptoms that are often mistaken for PCOS, such as:

  • Premature development of pubic hair
  • Irregular menstrual periods
  • Hirsutism (unwanted or excess body hair)
  • Severe acne (on the face and/or body)
  • Fertility problems in 10 percent to 15 percent of young women with CAH

Diagnosis of CAH

Congenital adrenal hyperplasia is transmitted genetically. Since CAH is an autosomal recessive disease, both parents must carry a defective enzyme trait to pass it on to their child.

Due to the genetic transmission of the condition, many people are aware of the risk in their family and let their doctor know of the need for genetic screening. The doctor may run blood tests to look for abnormal cortisol levels or other hormonal levels. Increased androgen levels may also be considered when making a diagnosis. A thorough family history record and physical exam are also necessary for the doctor to make a complete diagnosis.

Treatment Options

Birth control pills are usually effective in regulating the menstrual cycle, decreasing acne, and sometimes abnormal hair loss. If this is not effective in dealing with symptoms, or the doctor feels that birth control pills are not appropriate for you, he or she may consider giving you a low-dose steroid treatment. However, treatment is not typically lifelong.

For people with classic CAH with an aldosterone deficiency, a drug like fludrocortisone (Florinef) will retain salt in the body. Infants also receive supplemental salt (as crushed tablets or solutions), whereas older patients with classical forms of CAH eat salty foods.

The specific drug and regimen is usually up to the discretion of your physician and is dependent on the severity of symptoms.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Speiser PW. Congenital Adrenal HyperplasiaF1000Res. 2015;4(F1000 Faculty Rev):601. doi:10.12688/f1000research.6543.1

  2. National Adrenal Diseases Foundation. Congenital Adrenal Hyperplasia (CAH)

  3. US National Library of Medicine. 21-Hydroxylase Deficiency.

  4. UpToDate. Treatment of Classic Congenital Adrenal Hyperplasia.

By Nicole Galan, RN
Nicole Galan, RN, is a registered nurse and the author of "The Everything Fertility Book."