The doctor greeted her warmly. Then, more sternly, said: “It looks like you have a suntan. Have you been out in the sun?” It wasn’t the first time she heard that. “My friends keep saying that!” she exclaimed. She hadn’t been anywhere warm, didn’t go to tanning parlors, didn’t use tanning products. She didn’t know why her skin looked darker. And really, she felt so awful these days that she didn’t have the energy to even wonder about it.
Bock knew that some of his patients didn’t immediately acknowledge their tanning habits. But he could tell that wasn’t the case with this patient. He stepped out of the exam room and went to his office. At his computer, he searched for causes of hyperpigmentation. Two rare disorders came up immediately: hemochromatosis — an inherited disease in which patients are born without the chemicals needed to get rid of excess iron. Over time, these patients end up with too much iron in their system. When it collects in the pancreas, patients develop diabetes; in the joints, arthritis develops. And when it builds up in the skin, patients look darker.
The other disorder known to cause skin darkening is primary adrenal insufficiency (P.A.I.). The adrenals are triangular-shaped glands located on top of the kidneys. The tiny organs get their instructions from a natural chemical, ACTH (adrenocorticotropin hormone), which is made in the pituitary gland in the brain. When ACTH is released into the circulation, the adrenals deliver their load of hormones, including adrenaline and cortisol, which help the body respond to biological stresses like illness, hunger or fatigue. Another adrenal hormone, aldosterone, controls sodium levels, and through that, blood pressure. High levels of ACTH also stimulate melanocytes, the cells that make skin pigments.
In P.A.I., the gland and its machinery to make hormones are destroyed — usually by a misdirected immune system. Certain infections, including H.I.V., as well as tuberculosis and cancer can also destroy the glands. The most common symptoms of this rare disease are nausea, weakness and dangerously low blood pressure.
Bock hadn’t seen a case of either disease. But both can kill if not diagnosed and treated. “This is a long shot,” he told the patient, but worth investigating.
A few days later, the first batch of labs were back. These measured ACTH, the hormone that controls the adrenal glands. Normally just a whisper of ACTH is enough to get the adrenal glands working. But the woman’s test showed that the hormone was practically shouting — and was still not being heard. Her ACTH level — which is typically lower than 50 — was nearly 2,000. And even at that level, the expected adrenal-response hormone, cortisol, was barely detectable. She had primary adrenal insufficiency. The disorder, formerly known as Addison’s disease, was first described in 1855 by Thomas Addison, an English physician. Recently the medical community has moved away from eponyms, which reference the discovering doctor, to names that describe the disorders themselves.