You may have run into the term exclamation point hairs (or exclamation mark hairs) online while reading about Alopecia Areata, but what does it mean? What are they and how are they related to hair loss? If you are new to hair loss or have a loved one who is going through it, knowing the signs dermatologists look for in the diagnosis stage can provide clarity and certainty. We’ll go over what these unusual hairs are, what they mean, and how to identify them.
What is an exclamation point hair?
An exclamation point hair is a short, fragile hair that is thinner at the base where it attaches to the body than it is on the other end. The thinning of these hairs causes them to be structurally weak and eventually break, giving the hair shaft the characteristic appearance of an exclamation mark.
Exclamation mark hairs are thought to be caused by inflammation which is one of the symptoms of Alopecia Areata. This is why the presence of these hairs often lead a doctor or dermatologist to a diagnosis of Alopecia Areata. Inflammation causes weakness along the hair shaft which leads it to become thin and fragile, breaking easily.
What do these hairs mean?
Exclamation point hairs help your doctor or dermatologist determine the type of hair loss you are experiencing. Specifically, they can be a strong indicator of Alopecia Areata and rule out other causes.
In Alopecia Areata, these disordered hairs may be present around the edges of a patch of hair loss. Exclamation mark hairs may be present on various parts of the body in someone with Alopecia Totalis, which is the subtype of Alopecia Areata characterized by total loss of hair on the scalp. In Alopecia Universalis, all hair on the body is lost and exclamation mark hairs are not present. It is important to note that studies have shown these hairs can signify other causes of hair loss: trichotillomania, alopecia resulting from chemotherapy, and thallium poisoning.
What does an exclamation point hair look like?
These irregularly shaped hairs are noticeably shorter than regular hairs on your scalp, growing only 3-4 mm in length. Inflammation causes the hair shaft to develop weak points and eventually break, the resulting shape resembling an exclamation point. In contrast to normal hair which is thick near the base and is thinner moving outwards, these fragile hairs are thin where they attach to the skin and thick on the other end. They also tend to lose colour near the base of the hair shaft.
Exclamation point hairs may be visible around the patches of hair loss in a person with Alopecia Areata. Image Source DOI:10.2147/CCID.S10182
While visible to the naked eye, your dermatologist may use a dermatoscope to observe them more clearly along with other changes in your skin, hair, and nails.
Dermatoscope
How regular hairs are different from exclamation point hairs
Exclamation point hairs differ from normal hairs because they do not continue growing past the 3-4 mm mark. They become fragile because of the body’s inflammatory response, leading them to fall out. Additionally, an exclamation mark hair is thin where it attaches to the skin and is thicker at the other end, whereas regular hairs are thicker near the base and get thinner moving out. The presence of exclamation mark hairs may indicate that you have Alopecia Areata. As with any change or uncertainty in your health, consult your doctor or dermatologist to receive a proper diagnosis.
