AI: A Focus on Subtypes
Primary AI
Congenital Adrenal Hyperplasia
- 75% of classic CAH
- Cortisol + aldosterone deficiency
- Life-threatening (salt wasting); may develop salt wasting crisis without treatment
- Usually detected by newborn screening or in early childhood
- Can cause genital ambiguity in girls
- 25% of classic CAH
- Cortisol deficiency
- Less severe
- Can cause genital ambiguity in girls
- Most prevalent form of CAH
- Cortisol deficiency
- Mild
- Symptoms that mimic early puberty, such as pubic hair growth, increased body hair, body odor, and acne
- Some children do not experience symptoms or need treatment
Addison’s Disease
The primary cause of AI in adolescence is an autoimmune disease, also called Addison’s disease, in which a person’s immune system produces antibodies that attack and slowly destroy the adrenal glands. Often the body is unable to produce both cortisol and aldosterone. Except for salt craving, signs and symptoms are often nonspecific, such as vomiting, weight loss, abdominal pain, weakness, tiredness, muscle or bone pain, and anxiety. Without treatment, Addison’s disease could result in an acute life-threatening adrenal crisis.
X-Linked Adrenoleukodystrophy
Adrenal insufficiency is also noted in many individuals with adrenoleukodystrophy (ALD) , a rare genetic disease that affects boys and men. It results from defects in breakdown of very long chain fatty acids which accumulate and damage the protective sheath of the nerves in the brain. Symptoms include seizures and hyperactivity, as well as progressive worsening of speech, listening, and understanding verbal instructions.
Central AI
In central adrenal insufficiency, the pituitary gland and/or the brain do not make the hormones that trigger the adrenal gland to make steroids. This can be due to long term use of steroids (for example for asthma or juvenile idiopathic arthritis) or conditions that affect the brain and pituitary gland. Steroid medications suppress the production of one’s own steroid hormone from the adrenal gland, ultimately leading to adrenal insufficiency. Symptoms are often nonspecific and may include weakness, tiredness, upset stomach, poor weight gain, and headaches. Left untreated, this condition could lead to a life-threatening adrenal crisis.
