The Case of the Disappearing Eyebrows

DISCUSSION
This case illustrates several variants of an extremely common condition: alopecia areata (AA), literally translated as “hair loss confined to a particular localized area or areas.” Although AA is more common in adults, it often affects children. And though the scalp is by far the most commonly affected area, AA can cause hair loss anywhere on the body.

In general, the earlier the onset, the more likely the problem is to become recurrent or even progressive. In rare instances, a patient can develop alopecia totalis, in which there is permanent and total scalp hair loss, or even alopecia universalis, the permanent loss of every hair on the entire body. Other predictors of a poor prognosis include extensive involvement of the scalp, especially the periphery (termed ophiasis), and a history of atopy.

Much research has been done on the underlying pathology of AA, as well as potential remedies. This has proven, beyond any doubt, that the problem is autoimmune and tends to run in families (as with other autoimmune diseases), suggesting a hereditary basis. We also know that medications that dampen this autoimmune process, such as steroids and biologics, are useful but not always safe or practical.

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What we don’t really know is what triggers an actual attack. My observation, based on 35 years of dermatology practice, is that stress often plays a part—but I’d be hard pressed to prove that, and it wouldn’t be very useful even if I could. This patient adamantly agreed that stress was the trigger for his AA.

The differential for AA includes tinea capitis, discoid lupus, and lichen planopilaris. This patient’s multiple episodes over decades made the correct diagnosis clear. However, when the diagnosis is in doubt—other items in the differential commonly affect the scalp, although they may also manifest with redness, scaling, or swelling—a punch biopsy may be necessary to sort through the possibilities. Care must be taken to enter the skin parallel to hair follicles when the sample is removed.

Many treatments have been tried for AA, but none are reliably effective. In the vast majority of patients, the problem resolves itself. Treatments to try when needed include topical steroids, intralesional steroids, and topical immune stimulators (eg, squaric acid or dinitrochlorobenzene)—all of which have their limitations.

TAKE-HOME LEARNING POINTS

• Alopecia areata (AA) is more common in adults but can affect children as well.
• In rare cases, the patient can experience permanent total hair loss on the scalp (alopecia totalis) or the entire body (alopecia universalis).
• Because AA is an autoimmune disease, steroids and biologics may be useful treatments—but they are not always safe or practical.
• In a majority of patients with AA, the problem will resolve on its own.