What's Behind That Rash? - from Discover Magazine

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Vital Signs

What's Behind That Rash?

Benign but irritating skin eruptions signal much more

serious internal troubles

By Norman

DISCOVER Vol. 26 No. 11 | November 2005 | Biology &

Medicine

As a dermatologist, I see many skin disorders but

rarely anything so revealing—and misleading—at the

same time.

" There are lots of bumps coming up, " my new patient

told me.

Dozens of tiny yellow and pinkish eruptions ringed in

red were scattered over his chest, abdomen, upper and

lower extremities, and back.

" How long has this been happening? " I asked.

" Three months. I went to the walk-in clinic, and the

doctor said to come see you. "

" Did they do any tests? " .

" Nope. "

" Do these bumps bother you? " I asked.

" Sometimes. Kind of itchy. "

" Do you remember if they came on gradually or

suddenly? "

" It was like all at once. One day they just seemed to

be there. "

I checked his chart: 37 years old. He had a hernia

repair as a child and a history of unspecified back

surgery. Now he had hypertension and occasional

abdominal pain. He was taking medications for pain,

depression, and high blood pressure.

" Any particular diseases run in the family? " I asked.

" I was adopted when I was 2. I don't know anything

about my natural parents or family. "

" What about your diet? "

" Not real great lately. "

" Such as? "

" I eat about three gallons of ice cream and a bottle

of chocolate syrup every week. "

I noted this on his chart but said nothing. Doctors

are trained not to be judgmental. He was five foot

eight and weighed 230 pounds. His blood pressure was

142/88, and his pulse was 92. He had checked off " yes "

to smoking, 1.5 packs of tobacco a day for

approximately 20 years, and occasional alcohol use. He

said he didn't use illicit drugs.

For more clues, I shaved a bit of the skin eruption

for analysis, and I ordered tests of his fasting lipid

profile, complete blood count, and blood chemistry.

" What the heck is going on with me? " he asked.

" The growths are not any kind of cancer, but they

could be a sign of a problem inside. You need to get

the laboratory tests done as soon as possible. And

I'll be seeing you right after that. "

Before he left I made sure he was scheduled again for

an appointment and dictated a letter to the doctor

he'd seen at the walk-in clinic.

A few days later, the biopsy result confirmed my

suspicions: eruptive xanthoma, a type of benign skin

growth made up of macrophages (immune cells) filled

with fatty substances called lipids. Xanthomas are

associated with a condition in which

lipids—specifically, a type of fat called a

triglyceride—accumulate in the blood and elsewhere.

His lab tests showed that his total cholesterol was

almost 1,000 and his triglycerides close to 4,000,

both dangerously high. His glucose was elevated at

over 200, and his liver enzymes—an indication of

systemic problems that can accompany xanthomas—were

also up. I left a message on his answering machine to

contact me right away. About two hours later, I got a

call from his father.

" You're the dermatologist, right? "

" Yes, " I said.

" He had good things to say about you. I talked to him

about you just yesterday. "

" How is he doing? "

" Not so good. He's in the hospital with a heart

attack. Got up this morning and complained of chest

pain that kept getting worse. Luckily I was here to

rush him over there. "

His father told me where he was and who was treating

him.

" I appreciate your calling me, " I said. " Sorry he's in

bad shape. "

I arranged to have the patient's recent blood and

biopsy reports along with my contact information faxed

to the hospital.

Later, the attending doctor called. " I'm glad you sent

us your findings, " he said. " Your reports saved us a

lot of time and helped us get his treatment going in

the right direction. " He went on to explain that they

found severe premature atherosclerosis and an enlarged

left ventricle. " We're getting some more specific

tests, " he added. " He should be out of the ICU in a

couple of days if all goes well. If we keep him alive,

he'll be rooming with us for a while. "

" I'm sure it'll take time. But I have a question. I

have seen others with this problem, and they've had

pancreatitis. What's different here? "

" This guy was playing with fire, " the attending doctor

said.

" How's that? " I asked.

" We do routine toxicity tests, and he came back

positive for cocaine. High levels. So on top of this

lipid problem he was pushing his heart even harder. "

Many conditions that perturb lipid metabolism can

cause xanthomas, including diabetes, low thyroid, and

alcohol abuse, and in women, the use of estrogen. But

the doctor suspected a different explanation: Cocaine

use had heightened a preexisting genetic vulnerability

to heart problems.

The patient's prematurely narrowed arteries and high

lipid levels were strong clues. A variety of protein

defects can disrupt normal function and cause lipids

to accumulate in the blood, infiltrate the walls of

blood vessels, and form deposits on the skin. The

conditions are often inherited, and patients typically

develop atherosclerosis in their twenties or thirties.

Skin eruptions are a common symptom. The patient

didn't know his biological family's medical

vulnerabilities because he had been adopted.

In someone whose arteries are already prematurely

narrowed, cocaine use will make a heart attack even

more likely. Cocaine damages the heart by triggering

the release of epinephrine and norepinephrine,

hormones that cause arteries to constrict, force the

heart to work harder, and sometimes induce a spasm in

the coronary arteries. Cocaine also damages the heart

wall itself, although why this occurs is not well

understood. The relationship of cocaine use to heart

problems was first documented in the early 1970s, and

cardiovascular symptoms are now recognized as the most

common symptom of cocaine abuse.

Although chronic cocaine use could have provoked

accelerated atherosclerosis, the patient's high levels

of cholesterol and triglycerides had put a tremendous

strain on his cardiovascular system. His tobacco habit

had further heightened his risk because cigarette

smoke is believed to provoke inflammation in the

circulatory system.

A genetic test subsequently confirmed that he had

familial dysbetalipoproteinemia, a condition that

occurs in about 1 in 10,000 people. While he was

hospitalized, the patient began taking a

lipid-lowering drug. By interfering with the body's

ability to make triglycerides, it would help diminish

his cardiac problems and prevent pancreatitis.

I saw him again when he got out of the hospital a

month later. His plasma triglyceride levels had fallen

to less than 1,000 milligrams per deciliter, and the

xanthomas were beginning to disappear.

He looked a bit more relaxed than during his first

office visit. " I appreciate your getting those blood

tests and a skin sample. The doctor in the hospital

told me that helped save me. "

We talked about his drug use, his genetic

vulnerability, and how the xanthomas developed.

" I cleaned up my act, " he said.

" If you can be honest with yourself, it helps, " I

said. " And be truthful to your health care providers.

You almost lost your life. " If he used cocaine again,

I explained, it would be like a time bomb set to go

off.

" I ain't no terrorist, " he said. " Especially against

myself. "

Norman is a dermatologist in Tampa, Florida,

and the author of The Woman Who Lost Her Skin and

Other Dermatological Tales. The cases described in

Vital Signs are true stories, but the authors have

changed some details about the patients to protect

their privacy.

I saw him about six months later. This time his blood

fats were getting back to normal levels, and the

xanthomas had almost vanished. He had confronted an

unknown genetic legacy and a self-destructive drug

habit, and he was lucky to be alive.

WARNING SIGNS When a person has problems

metabolizing cholesterol and triglycerides, those

substances may accumulate in patches on the skin

called xanthomas. The pinkish or yellow patches

consist not only of extracellular lipids but also

scavenging immune cells

There are many sources on the Web for more information

about hyperlipidemia, including the American Heart

Association (www.americanheart.org) and VascularWeb

(www.vascularweb.org).