DISCUSSION
Hair loss, collectively termed alopecia, is a disturbing development, especially in a child. In this case, we had localized hair loss most likely caused by behavior that was not only witnessed by the boy’s parents but also admitted to by the patient. (We’re not always so fortunate.) Thus, it was fairly straightforward to diagnosis trichotillomania, also known as trichotillosis or hair-pulling disorder. This condition can mimic alopecia areata and tinea capitis.
In this case, the lack of epidermal change (scaling, redness, edema) and palpable adenopathy spoke loudly against fungal infection. The hair loss in alopecia areata (AA) is usually sharply defined and complete, which our patient’s hair loss was not. And the blood work that was done effectively ruled out systemic disease (an unlikely cause of localized hair loss in any case).
The jury is still out as to how exactly to classify trichotillomania (TTM). The new DSM-V lists it as an anxiety disorder, in part because it often appears in that context. What we do know is that girls are twice as likely as boys to be affected. And children ages 4 to 13 are seven times more likely than adults to develop TTM.
TTM can involve hair anywhere on the body, though children almost always confine their behavior to their scalp. Actual hair-pulling is not necessarily seen. Manipulation, such as the twirling in this case, is enough to weaken hair follicles, causing hair to fall out. In cases involving hair-pulling, a small percentage of patients actually ingest the hairs they’ve plucked out (trichophagia). Being indigestible, the hairs can accumulate in hairballs (trichobezoars).
Even though TTM is most likely a psychiatric disorder lying somewhere in the obsessive-compulsive spectrum, it is seen more often in primary care and dermatology offices. Scalp biopsy would certainly settle the matter, but a better alternative is simply shaving a dime-sized area of scalp and watching it for normal hair growth.
Most cases eventually resolve with time and persistent but gentle reminders, but a few will require psychiatric intervention. This typically includes habit reversal therapy or cognitive behavioral therapy, plus or minus combinations of psychoactive medications. (The latter decision depends on whether there psychiatric comorbidities.) Despite all these efforts, severe cases of TTM can persist for years or even a lifetime.
It remains to be seen how this particular patient responds to his parents’ efforts. It was an immense relief for them to know the cause of their son’s hair loss and that the condition is likely self-limiting.
TAKE-HOME LEARNING POINTS
• Trichotillomania (TTM) is an unusual form of localized hair loss, usually involving children’s scalps.
• TTM affects children ages 4 to 13 and at least twice as many girls as boys.
• TTM does not always involve actual plucking of hairs. Repetitive manipulation, such as twirling, can weaken the hairs enough to cause hair loss.
• Unlike alopecia areata (the main item in the alopecia differential for children), TTM is more likely to cause incomplete, poorly defined hair loss in an area where hairs of varying length can be seen.
• Usually self-limiting, TTM can require psychiatric attention, for which a variety of habit training techniques can be used.