Patient history is key when assessing hair loss

Denver - When patients present with hair loss, dermatologists should focus most heavily on patient histories, according to an expert who spoke at the 72nd Annual Meeting of the American Academy of Dermatology.

Many dermatologists perform a cursory exam and order a battery of blood tests, says Leonard Sperling, M.D., chairman and professor of dermatology, Uniformed Services University of the Health Sciences, Bethesda, Md. Dermatologists often dread these encounters, he adds, because they can burn daylight and often reveal problems that can't be treated successfully.

Rather, in assessing symptom onset, "The magic question is, 'When was the last time you had a perfectly normal head of hair? Or when was last time you didn't have to think about your hair?' That will take you from 'It started six months ago' to 'It hasn't been quite normal for the last five or 10 years.' It's a very helpful question in assessing onset and duration," he suggests.

Many medications have been associated with alopecia, but the major players include retinoids, anticoagulants, anticonvulsants, beta blockers and interferon alpha (plus heavy metals), Dr. Sperling adds.

Regarding the examination, "Patients occasionally come in with a Baggie of hair. Don't fear the Baggie," he says. Set it aside and telling the patient you'll examine it later, but right now, you need a fresh sample. "Everybody understands the concept of a fresh sample."

Sample-taking techniques include the following:

• The gentle hair pull, which in normal patients produces no more than two telogen hairs;

• The forcible pluck, which normally produces about seven percent telogen hairs;

• Timed hair counts - tallying how many hairs fall out during a minute of brushing (zero to 80 is normal).

Overall, Dr. Sperling says, "The most important part is the pattern of hair loss. When you send a biopsy to a pathologist, at least describe the pattern of hair loss - that can make a very big difference." For example, diffuse hair loss that spares the occiput tends to signal androgenetic alopecia in females.

"Here's another tip: any African-American child who has a scaly or inflamed bald spot, or just a bald spot, has tinea capitis until proven otherwise. This is useful to remember. You make the diagnosis by scraping out the little stubs of hairs. When you look under the microscope, the little stubs are packed with spores. Or you can do a culture, which usually grows out Trichophyton tonsurans," Dr. Sperling says.