Medical Mysteries: Dermatologists couldn't explain woman's endless itching

Susan Benda suffered for more than a year before getting the right diagnosis.
Susan Benda suffered for more than a year before getting the right diagnosis. (Tracy A. Woodward/The Washington Post)
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By Sandra G. Boodman
Special to The Washington Post
Tuesday, April 20, 2010

For Susan Benda, the ritual was becoming routine: She would awaken in the middle of the night and pad to the bathroom, then stick her head under a steaming hot shower. That was the only way to briefly quell the infuriating scalp itch that had plagued her for more than a year.

A lawyer for the federal government who lives in the District, Benda had amassed an impressive array of shampoos, ranging from cheap drugstore brands to expensive prescription remedies, some foul-smelling, others floral-scented. She had consulted three dermatologists, one of whom said her unremitting itching, which grew worse at night, had a psychiatric cause; the other two said it was allergic. Her internist had raised the ominous prospect of cancer. She had undergone a biopsy on her neck to check for a rare digestive problem after a mysterious itchy rash appeared there.

In February, when an allergist took one look at Benda's neck and told her what was really wrong, she was dumbfounded.

"Do I laugh or do I cry?" she remembers thinking. "What kept the doctors from seeing what I have? And why didn't I think of it?"

* * *

In August 2008 Benda made an appointment with a well-known Washington dermatologist; her head had been itching for several weeks. As the doctor inspected her scalp, Benda described the problem and said it felt as though "red ants were crawling all over my head." That description, and the lack of any apparent cause, led the doctor to tell Benda her itch was neurotic in origin.

Insulted, Benda began experimenting with different shampoos, thinking she might be allergic to an ingredient. At the time, she also decided to let her very thick, wavy brown hair grow long.

In November, while visiting her mother in Connecticut, Benda mentioned the problem to a close family friend, a dermatologist who lived next door. She checked Benda's scalp and told her she couldn't see anything that would account for the itch. The doctor recommended Benda take antihistamines; they reduce itchiness, which can trigger frequent scratching and set up a vicious cycle. Benda took one drug; when it didn't work, she tried another.

By February 2009, it was clear antihistamines were not the answer. She made an appointment with dermatologist No. 3, who peered at her scalp and prescribed a cortisone shampoo.

For months Benda, a single mother of a middle school student, tried to manage the itching. She wondered if the first dermatologist might be right. Return visits to the third dermatologist yielded nothing.

In September, during her annual physical with her longtime internist, she mentioned the problem. The internist prescribed an antifungal shampoo and told Benda that if the itching persisted, she should get a CT scan to check for lymphoma, "just to err on the side of caution." Unexplained itching is a symptom of some cancers, and Benda felt a cold dread. Two close friends were battling the disease, and in her worst moments she worried whether she might be next.

By January 2010, Benda, 53, noticed a new symptom: A red, bumpy, raised and, of course, itchy rash covered the back of her neck, under the cascade of hair she hadn't had cut in more than a year. She returned to the third dermatologist, who decided to biopsy the site. He told Benda he suspected she might have dermatitis herpeteformis, a rash related to celiac disease, which is marked by an inability to digest gluten found in wheat. The doctor excised a tiny piece of skin and sent it to the lab.

Benda felt oddly relieved, then unsettled, after she looked at a picture of the celiac skin rash on the Internet: It looked nothing like her rash. A week later, she went back to have the stitches removed and was told she didn't have dermatitis. When she told the dermatologist that the picture she'd seen didn't resemble whatever was on her neck, he was dismissive. The lab report suggested two other causes: a drug reaction or hives, the possibility the dermatologist considered most likely. Keep taking antihistamines, he told her.

Over lunch with her brother a few days later, Benda told him the whole story. He suggested she consult his allergist, Michael Kaliner of Chevy Chase, for a work-up.

On Feb. 16 she recounted the story to Kaliner and told him that she was "itchy beyond agony." The veteran allergist took one look at the back of her neck and told Benda the cause wasn't hives.

"I think I know what you have," Kaliner told her. "It's lice." He then snipped off a lock of hair and, with his nurse and his shocked patient, examined the specimen clinging there -- an unmistakable louse -- under a microscope.

"It was the worse case I've ever seen," Kaliner recalled. "Every hair was infested," and the insects were visible. Kaliner said that the neck rash was the tip-off: It sometimes accompanies lice and is caused by irritation from their droppings.

Head lice -- tiny parasitic insects -- live on the scalp and neck hairs of human hosts, feeding on their blood. They do not reflect socioeconomic status or cleanliness, notes the Harvard School of Public Health Web site. Lice are usually acquired by direct head-to-head contact with an infested person's hair, but they can also be acquired from bedding, upholstered furniture or clothing such as hats.

While the head of a person with an infestation typically has fewer than a dozen active lice on the scalp, it may contain hundreds of viable or dead eggs called nits.

"My initial reaction was to cry," Benda recalled. "I couldn't believe that I hadn't thought of it." More than a year earlier, shortly before she'd seen the first dermatologist, Benda had treated her son for lice. She had also treated herself, but apparently not well enough.

After shock came anger. "I kept being treated like somebody who was a head case," she said. She couldn't understand why none of the doctors had asked if she'd ever had a similar problem before. "And I didn't think of [lice], because I'd already treated it."

Kaliner sees a case or two of head lice annually in patients who have consulted him for what is presumed to be allergic itching. He said he is amazed none of the other doctors spotted Benda's obvious problem. "Usually it's much more subtle," he said.

Benda used several strong chemical treatments for lice, including one that smelled like kerosene and stung horribly because her scalp was so abraded from scratching. She and her son spent hours getting their hair methodically combed and inspected by a suburban Maryland woman who calls herself a nitpicker. Benda said the woman combed more than 500 nits and dead lice out of her hair.

Soon afterward she called the dermatologist who performed the biopsy to tell him what happened; he apologized. On March 1 she sent him a $368 bill for the nitpicker's services. "But for your failure to diagnose my lice, I don't think it would have come to this," she wrote, citing her "year of distress."

He responded the next day. "I regret that I did not make the diagnosis sooner," he wrote, enclosing a check for $275. By cashing it, he added -- noting that he had consulted his lawyer -- Benda would be releasing him from "all further liability."

She cashed the check, but the events leading up to her diagnosis still rankle. "It's a huge relief not to wake up in the morning itching," Benda said. She has mixed feelings about having enough shampoo to last for years.

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