Losing it: A rational approach to hair loss

Fun facts about the hair cycle, five questions about the condition, and treatment options can help internists address an emotional topic for patients.


My hair is falling out.” These five words can change the course of a visit, especially when the physician is reaching for the doorknob, said Patricia G. Malerich, MD, staff dermatologist at Geisinger Health System in State College, Pa. In addition to a hefty differential, hair loss is accompanied by heightened emotions because hair has many social, religious, and personal meanings, including social identity, she said. “This is the classic ‘Oh, by the way’ complaint. … But it is really important that you sit down because it's a human issue.”

During the Dermatology for the Internist precourse at Internal Medicine Meeting 2019, Dr. Malerich provided an efficient and organized approach to hair loss that, at its root, focuses on patient education.

Fun facts and exam tips

Central to the session were the four phases of hair follicle growth: anagen (growth, 1,000 days on average), catagen (transition, 10 days), telogen (resting, 100 days), and exogen (shedding). When counseling patients, Dr. Malerich draws the four-phase cycle, even sneaking in a resting cat after “catagen” to help them remember the lull that happens after the transition phase.

She reviewed more fun facts about the hair cycle. On average, hair grows about 1 cm per month (which varies seasonally), and there is a mosaic pattern of growth. “Our hairs are on all different phase cycles,” Dr. Malerich noted. “When babies are born, they have a homogeneous cycle, so that's why they will lose all their hair, and then they'll start growing in this mosaic pattern.”

Of the 100,000 hairs on the scalp, an average of about 150 hairs are shed in a normal daily exogen phase, “which is a lot more than people would think,” she said. Certain factors, such as shampooing habits, can affect this number, which you may not want to bring up to every patient. “The only way I caution you in bringing this up is because then you'll have hair counters” who bring lost hairs in plastic baggies as evidence, Dr. Malerich said.

In general, 85% to 90% of hairs are in a growing phase, with fewer than 1% in a catagen phase and 10% to 15% in a telogen phase, she said, adding that each follicle has 20 life cycles. “You do have a finite amount of hair growth,” said Dr. Malerich.

That last fact may be more depressing than fun to some patients, she said, but education has its benefits. “I think that helps your relationship with your patients, and I think that they'll be more in tune with what's going on with their body if they understand what's happening.”

When a patient mentions hair loss, don't panic. Instead, respond with a thoughtful history that addresses these “big five” questions:

  1. 1. Tell me about the hair loss. Do you feel it is all-over shedding or clumps of loss? Pain, scale, itch? “You want to establish your pattern and your symptoms of loss,” said Dr. Malerich.
  2. 2. How long have you noticed this loss?
  3. 3. Any recent change in medications?
  4. 4. Any recent change in health status (e.g., serious illness, trauma, childbirth)?
  5. 5. Do you have a family history of hair loss in both men and women?

To that last point, Dr. Malerich added that many people believe only genes from the mother's or father's side influence hair loss, but this is not true. “It's really polygenetic, and it can come from either side.”

When diagnosing hair loss, be sure to ask whether the alopecia is non-scarring or scarring. Scarring alopecia, which includes a loss of the follicles, involves diagnoses that are outside the internist's realm of treatment, she said. “You could refer, but you could also biopsy,” said Dr. Malerich, adding that two 4-mm punch biopsies that extend to the fat are preferred (one for horizontal sectioning, one for vertical sectioning).

Making the diagnosis

The internist's focus should be on non-scarring alopecia, which falls into three categories: diffuse loss, circumscribed loss, and patterned loss.

Some clues that indicate diffuse loss are a history of more hair than usual on pillows, clothes, and shower drains (up to 400 hairs a day, per those hair counters), Dr. Malerich said. On exam, a hair-pull test involves grasping 40 hairs between the thumb and forefinger and applying a slow pull. More than four to six hairs is an abnormal test (two to three if the patient recently shampooed). “It's a little hard. People don't take lightly to pulling on their hair, and in this day and age, I would tell them, ‘Permission to approach and pull your hair?’” she said.

In cases of diffuse loss, either telogen or anagen effluvium (Latin for “a flowing out”) may be the culprit. The former is a rapid shift in the hair growth cycle, which occurs about 100 days after a metabolic alteration or precipitating event (e.g., childbirth, physical stressors, medications). “Telogen effluvium can last—are you ready for this?—six to eight weeks,” said Dr. Malerich. “They're not going to like what you have to say, [but] complete regrowth is expected.” In contrast, anagen effluvium is not a true shed but a disruption in the growing phase, usually caused by radiation to the scalp or systemic chemotherapy, she said.

Circumscribed alopecia, or patchy hair loss, could be attributed to alopecia areata, tinea capitis, or trichotillosis. In alopecia areata, which commonly relapses over a lifetime, spontaneous remission is more likely if the patient has focal patchy loss, has no associated atrophy, and has recent onset, Dr. Malerich said. Tinea capitis, which involves a round patch of loss with scale and weeping, warrants a potassium hydroxide test, and trichotillosis, which involves patients pulling their own hair, will present in irregular shapes, she said.

Finally, and most notoriously, is patterned loss: male- and female-pattern alopecia. Frequency and severity increase with age, with 80% of Caucasian men and 50% of Caucasian women showing evidence of androgenic alopecia by age 70 years, Dr. Malerich said. The classic male pattern involves frontal loss, top loss, and vertex loss, whereas the female pattern involves retaining the front hairline but losing from the top, creating a widening of the part in a Christmas tree pattern with a frontal accentuation, she said. Women who have severe or early onset of a male pattern warrant a lab workup, including testing for dehydroepiandrosterone sulfate, testosterone (free and total), and 17-hydroxyprogesterone, Dr. Malerich said.

“I say that I give a lot of bad diagnoses, but this diagnosis induces the most tears. Sometimes you don't want to go in the room because you know that people are going to be upset and they're going to cry,” she said. “We can't do much to fix it.”

Treatments for patterned hair loss

While there are no magic-bullet fixes for patterned hair loss, patients have some treatment options. Topical minoxidil can prolong the anagen phase, can enlarge the hair shaft, and is postulated to have calcium channel-opening activity, Dr. Malerich noted. While the over-the-counter medication is marketed as a 2% formulation for women (in a pink box) and 5% for men (in a blue box), “There's nothing I could find that says women can't use the 5%,” she said.

Minoxidil comes in a solution and a foam. While the solution can cause allergic contact dermatitis, the foam is more expensive because it's still patented, she noted. Patients will apply 1 mL twice a day, but application can be tricky. “You're supposed to divide the part [of the hair], put it in, divide it again, put it on, divide it again. It's a lot of work,” Dr. Malerich said.

She warned that stopping the medication may lead to resumption of hair loss. In addition, treatment with minoxidil involves a paradoxical worsening of hair loss for four to six weeks, Dr. Malerich said. “That will freak [patients] out because every hair on their head is precious to them,” she said. To prepare patients for this news, Dr. Malerich uses an analogy of having soldiers in a line, with half of them sitting down, and then kicking out the seated soldiers so the walking ones can fill in. “That's what you're doing. You're shifting from telogen, or the resting phase, into a growing phase. You want everyone in synchronous growing phase,” she said.

Another treatment is finasteride (1 mg/d), a 5-alpha-reductase inhibitor (type 2). Patients may already be aware of potential side effects, such as loss of libido or erectile dysfunction, Dr. Malerich said, “But that's actually only 2% of men that take it.” In studies, about 90% of men taking finasteride had halted loss and 65% had partial regrowth over six months, which is “pretty impressive,” Dr. Malerich said. “Again, though, if they don't want to take the medication anymore, they're going to resume loss.”

There is a big debate about finasteride and prostate cancer. In studies of patients, most of whom had benign prostatic hyperplasia and were taking 5 mg daily, the overall incidence of high-grade prostatic carcinoma was reduced, but there was a possible increased risk in those who had prostate cancer, she said. When screening for prostate cancer in patients taking finasteride, Dr. Malerich suggested increasing the prostate-specific antigen limit by 40% to 50%.

Women with female-pattern hair loss can also use finasteride or dutasteride, another 5-alpha-reductase inhibitor (types 1 and 2), although oral medications have less predictable outcomes, she noted. “You always have to be cautious in women who are childbearing or have a history of breast cancer,” Dr. Malerich said.

Ultimately, physicians have no “crystal ball” to provide information on whether patients' hair will continue to fall out, or how much of it will remain, she said. “Say someone uses [a treatment] for 10 years, stops it, and then their hair doesn't really fall out. So then they're mad because they've been using this and their hair wasn't going to fall out,” Dr. Malerich said. “You don't know. It's sort of a gamble.”