What does it look like?

The hair loss in alopecia areata is non-scarring and localized. The patches are typically round or oval in shape and well circumscribed with complete loss of hair. It may affect the scalp or other areas such as eyebrows, eyelashes and facial hair. Exclamation point hairs are a classic finding and are best seen with magnification. These are hairs, which taper closer to the scalp, resembling an exclamation point. Nail pitting can be seen. There are several variants of alopecia areata that are particularly difficult to treat. Alopecia totalis is complete loss of hair on the head and alopecia universalis is loss of hair on the entire body. Ophiasis is hair loss around the occiput (hair line on the back of the scalp) and is seen mostly in children.

How is it diagnosed?

The diagnosis is usually clinical and typically does not require a biopsy. A thorough history and physical should be done to assess for associated disorders, particularly thyroid disease. Bloodwork can be ordered if there is any concerning signs or symptoms but does not need to be performed routinely.

How is it treated?

Hair will often regrow on its own within affected patches. However, a new patch somewhere else is likely to appear in the future, and the overall course of the disease is unpredictable. If patients are motivated and can tolerate needles, treatment is usually with local intradermal injections of steroids (triamcinolone 2.5 mg/cc). In young patients and those who cannot tolerate intralesional therapy, Potent topical steroids can be utilized. Topical minoxidil has been helpful in some patients, particularly once new growth begins. Application of irritants and allergens, such as anthralin or DPCP/squaric acid, can be performed, but are not always well tolerated. For patients with severe and widespread disease, systemic medications such as pulse steroids, methotrexate, and JAK inhibitors can be considered.

What is the differential diagnosis?

Tinea capitis is a superficial fungal infection of the scalp. Usually, it can be distinguished from alopecia areata by the presence of scale and redness. The hairs may also be broken off near the scalp creating a “black dot” appearance. A scraping for KOH prep can confirm the diagnosis. Treatment is with oral antifungals (See Ch. 6).

Trichotillomania is a self-induced condition, wherein hair loss is cause by pulling or twirling of the hairs. It is often associated with anxiety, stress or behavioral conditions. Clinical clues include patches of hair loss with sharp, angular borders and twisted and broken hairs of varying lengths. Consultation with psychology can be useful to address the underlying cause.

Traction alopecia is hair loss due to frequent or prolonged mechanical strain on hairs. It is most commonly seen in children who wear their hair in tight braids, pony tails, or whose hair is tied back under a turban. The hair loss is usually noted wherever hair has the highest degree of strain. Change in hair-care practices can help reverse the condition.

Secondary syphilis is sometimes associated with a “moth-eaten” alopecia. Usually patients also have a diffuse rash and other symptoms such as low-grade fever and fatigue. Syphilis is increasingly common in North America, so a sexual history may be relevant in adolescent patients to decide if this condition is on the differential.