Exclamation Mark Hairs in Alopecia Areata Occur at Perimeter of Patch

Where do you find exclamation mark hairs in alopecia areata?

Alopecia areata (AA) is an autoimmune disease that affects 1.7 % of the world’s population. Many patients with AA develop one or more so called “patches” of hair loss which may be circular or oval. Some patients develop a single patch whereas others develop many patches. A characteristic feature of patches of alopecia is that are often devoid of hair and are therefore quite smooth and bare. At the perimeter of the patches, characteristic “exclamation” mark hairs can often be seen. These are short 4 mm hairs which are essentially broken hairs. This photo shows a relatively large patch of alopecia areata.

Exclamation mark hairs were clearly noted at the perimeter. Monthly steroid injections with triamcinolone acetonide lead to complete regrowth in a matter of months.