Underactive adrenal glands

What is Addison's disease?

Addison's disease is the result of an underactive adrenal gland. An underactive adrenal gland produces insufficient amounts of cortisol (a steroid hormone that helps to control the body's use of fats, proteins, and carbohydrates, suppresses inflammatory reactions in the body, and affects immune system functions) and aldosterone (a steroid hormone that controls sodium and potassium in the blood). Four in every 100,000 people have Addison's disease. Onset of the disease may occur at any age.

What causes Addison's disease?

Often, the cause of the disease is unknown (idiopathic). Some Addison's disease cases are caused by the actual destruction of the adrenal glands through cancer, infection (tuberculosis), an autoimmune process, or other diseases (adrenoleukodystrophy) . Other causes may include the following:

• Use of corticosteroids as a treatment (such as prednisone) may cause a slow-down in production of natural corticosteroids by the adrenal glands.
• Certain medications used to treat fungal infections may block production of corticosteroids in the adrenal glands.

Rarely, Addison's disease is inherited as an X-linked trait, where the gene responsible for the condition is located on the X chromosome and passed down from a healthy female carrier to her sons (50/50 chance), who are affected. In this form, symptoms typically begin in early childhood or adolescence. Examples include adrenoleukodystrophy and adrenal hypoplasia.

What results from inadequate corticosteroid production?

Lack of adrenal hormones may cause:

• Elevated levels of potassium
• Extreme sensitivity to the hormone insulin, which normally is present in the bloodstream. This sensitivity may lead to low blood sugar levels.
• Increased risk of low blood pressure or shock during stressful periods, such as surgery, infection, or injury. Corticosteroids play an important role in helping the body fight infection and promote health during physical stress.

What are the symptoms of Addison's disease?

Mild Addison's disease symptoms may only be apparent when the child is under physical stress. The following are the most common symptoms of Addison's disease. However, each child may experience symptoms differently. Symptoms may include:

• Weakness
• Fatigue
• Dizziness
• Rapid pulse
• Darker skin (first noted on hands and face) than is present in other family members
• Bluish-black discoloration around the nipples, mouth, rectum, scrotum, or vagina
• Weight loss
• Dehydration
• Loss of appetite
• Intense salt craving
• Muscle aches
• Nausea
• Vomiting
• Diarrhea

If not treated, Addison's disease may lead to severe abdominal pain, extreme weakness, low blood pressure, kidney failure, and shock - especially when the child is experiencing physical stress. The symptoms of Addison's disease may resemble other problems or medical conditions. Always consult your child's physician for a diagnosis.

How is Addison's disease diagnosed?

In addition to a complete medical history and physical examination, diagnostic procedures for Addison's disease may include blood tests to measure adrenal hormone levels.

Treatment of Addison's disease

Specific treatment for Addison's disease will be determined by your child's physician based on:

• Your child's age, overall health, and medical history
• Extent of the disease
• Your child's tolerance for specific medications, procedures, or therapies
• Expectations for the course of the disease
• Your opinion or preference

The goal of treatment is to replace the adrenal gland hormones to allow normal function, Since Addison's disease can be life threatening, treatment often begins with administration of corticosteroids. Corticosteroids, such as hydrocortisone and prednisone, may be taken orally or intravenously, depending on the child's condition. Usually the child must continue taking the corticosteroids for the rest of his/her life. Treatment may also include taking a medication called fludrocortisone that helps restore the body's level of sodium and potassium.