"Anisotrichosis" refers to a variation in the thickness of hair follicles that is commonly seen in androgenetic alopecia. In early stages of AGA, most hairs are relatively thick in caliber but some of course are thin. Over the course of AGA more and more follicles becomes thin and very thin which extends the spectrum of follicle sizes seen.
Reference
Sewell L et al Anisotrichosis: A novel term to describe pattern alopecia. J Am Acad Dermatol 2007; 56: 856.
This article was written by Dr. Jeff Donovan, a Canadian and US board certified dermatologist specializing exclusively in hair loss.
Tapered & Exclamation Hairs in AA indicate Activity
Tapered Hairs
Tapered hairs are frequently seen in patients with small circular patches of alopecia areata. In contrast to 4-5 mm exclamation mark hairs (see next post), tapered hairs are long and typically as long as neighboring hairs. As the hair enters into the skin it becomes much thinner. At the bottom of the tapered hair (deep under the skin) is inflammation.
Tapered are important findings in patients with patchy stage alopecia areata as they tell us that the condition is active and that anti-inflammatory type treatments (such as cortisone injections) are likely to help. The above photo shows several tapered hairs (TH).
Exclamation Hairs
Exclamation mark hairs are frequently seen in patients with small circular patches of alopecia areata. These hairs a short 4-5 mm hairs and represent broken hairs. The top is thick and the end is often frayed. As the hair enters into the skin it becomes much thinner. At the bottom of the exclamation mark hair (deep under the skin) is inflammation. Exclamation mark hairs are important findings in patients with patchy stage alopecia areata as they tell us that the condition is active and that anti-inflammatory type treatments (such as cortisone injections) are likely to help. The photo shows several exclamation mark hairs (EMH).
This article was written by Dr. Jeff Donovan, a Canadian and US board certified dermatologist specializing exclusively in hair loss.
This week, we'll start a five day look at androgenetic alopecia in men (also called male pattern balding). The identification of so called "vellus" hairs is important in understanding male balding. Vellus hairs are tiny hairs less than 30 micrometers in diameter. They are present on the normal nonbalding scalp but only in low proportions. In male balding, the proportion of vellus hairs rises considerably as large "terminal" hairs are converted to tiny "vellus" hairs. In advanced balding, the vellus hairs disappear leaving a completely bald scalp in the affected areas.
This article was written by Dr. Jeff Donovan, a Canadian and US board certified dermatologist specializing exclusively in hair loss.
Vellus hairs are tiny, short non-pigmented hairs. They are fine hairs with a caliber less than 30 micrometers by definition. It is not common to find vellus hairs on the scalp in an individual without hair loss. On a normal scalp only about 1 of every 25 hairs are vellus hairs. Most hairs on the scalp are large pigmented terminal hairs. During the course of male and female androgenetic alopecia, vellus hairs become more prevalent and may even become the dominant hair type (outnumbering terminal hairs) in advanced balding cases.
Reference
Ko JH et al. Hair counts from normal scalp biopsy in Taiwan. Dermatol Surg. 2012
This article was written by Dr. Jeff Donovan, a Canadian and US board certified dermatologist specializing exclusively in hair loss.
Diagnosing hair loss in patients with darker skin types employs the same principles as for lighter skin types. However, a few features are unique including the the greater likelihood for scalp inflammation to create areas of hypopigmentation and hyperpigmemtation. In this picture of a male with androgenetic alopecia several findings are present. The redness and fine scale is consistent with seborrheic dermatitis. The patient also has folliculitis and a pustule can be seen in the upper portion of the picture. In the bottom left of the picture, areas of whitish hypopigmentation can be seen and in the bottom right areas of darker hyperpigmentation can be seen. The tiny white dots that are speckled al over the scalp represent the openings of the eccrine glands.
This article was written by Dr. Jeff Donovan, a Canadian and US board certified dermatologist specializing exclusively in hair loss.
Alopecia areata is an autoimmune condition that affects approximately 2 % of the worlds population. Many treatments are available. For patches of alopecia areata, the most effective treatment is steroid injections. When the scalp is examined a few weeks after a patient has received steroid injections a mixture of hair regrowth and hair loss is typically seen. In alopecia areata, hairs that are in the losing stage include broken hairs (arrow) and so called exclamation mark hairs (asterisk). Over time as hair growth dominates, the proportion of broken hairs and exclamation mark hairs will be reduced.
This article was written by Dr. Jeff Donovan, a Canadian and US board certified dermatologist specializing exclusively in hair loss.
Exclamation mark hairs are short hairs that are thick at the top and thinner as they enter the scalp. These hairs are known to occur in the autoimmune condition alopecia areata but also can occur in trichotillomania (shown this picture), poisoning situations (ie thallium) and have also been reported in dissecting cellulitis.
This article was written by Dr. Jeff Donovan, a Canadian and US board certified dermatologist specializing exclusively in hair loss.
"Trichotillomania" refers to a form of hair loss where an individual pulls their own hair. It can sometimes be simply a habit - especially in very young children. In adolescents, the diagnosis of trichotillomania may signify underlying psychological illness including depression, anxiety, and eating disorders.
Trichotillomania, alopecia areata and tinea capitis are the three most common diagnoses in children followed by telogen effluvium and androgenetic alopecia. One must always at least consider this diagnosis as it is easy to miss. The presence of broken hairs, black dots, hairs of different length, and other trichoscopic features a v-sign, tulip hairs, and exclamation hairs are helpful in arriving at the diagnosis. The picture shows numerous scattered broken hairs (see green dots) in a young child with trichotillomania.
This article was written by Dr. Jeff Donovan, a Canadian and US board certified dermatologist specializing exclusively in hair loss.
Lichen planopilaris (LPP) is a type of scarring hair loss condition. Patients frequently present with scalp itching, and sometimes scalp burning and tenderness. Increased hair shedding is common in the early stages. Hair loss is generally permanent and treatment helps stop the disease or at least slow down progression.
Clinically, dermoscopy (trichoscopy) of LPP often shows perifollicular erythema and perifollicular scale (follicular keratosis).
These findings are not present in all forms of LPP. A less common presentation of LPP is shown in the photo. Patients have hair loss with scalp itching. However, by dermoscopy they have many single hair follicles growing in a base of redness. This is what I have termed the "sea of singles" (SOS) appearance to describe the numerous single hairs and absence of hair follicle units containing 2 and 3 hairs. This form of LPP is similar to Abbasi's subtype described in 2016 and fibrosing aloepcia in a pattern distribution described by Zinkernagel in 2000. The "SOS" trichoscopic appearance is important to remember and provides a clue that the patient may have a scarring alopecia.
Reference
Zinkernagel MS et al. Arch Dermatol 2000
Abassi A et al. Dermatol Surg. 2016.
This article was written by Dr. Jeff Donovan, a Canadian and US board certified dermatologist specializing exclusively in hair loss.
I frequently get asked if wearing hair extensions is okay. Often it is fine, but one needs to monitor over time if any hair damage is occurring. Individuals feeling pain, "pins and needles" should consider loosening the extensions or changing the method of application. Individuals showing clinical signs in the office of hair damage may also consider changing the method of application.
Consider the patient shown in this picture. She has been using extensions for some time now. She has a few broken hairs (labelled B) and several miniaturized hairs (labelled V for vellus) in any area that did not previously show miniaturization. These two signs are evidence of hair damage. A recommendation was made to change the extension in this case and treatment with a corticosteroid was given to reduce inflammation that is common in such cases of early traction alopecia.
This article was written by Dr. Jeff Donovan, a Canadian and US board certified dermatologist specializing exclusively in hair loss.
Dissecting Cellulitis (DSC), is a rare scarring hair loss condition that is characterized by deep inflammation and leads to the formation of draining sinus tracts (especially tunnels that allow pus and inflammation to escape). The diagnosis of DSC in advanced stages is easy as these openings (sinus tracts) can be seen all over the scalp. In early stages, up close exam and use of a dermatoscope can prove extremely helpful.
Early DSC is characterized on dermoscopy by large yellow dots, thin vellus hairs within the area, broken hairs and healing (covered) or open sinus tracts. This picture shows a sinus tract at an earlier stage than the picutre yesterday (panel 4 in our 5 day series). There is inflammation in the skin which gives a red color.
This article was written by Dr. Jeff Donovan, a Canadian and US board certified dermatologist specializing exclusively in hair loss.
We will continue our week's theme of Dissecting cellulitis (DSC), a rare scarring hair loss condition. It is characterized by deep inflammation and leads to the formation of draining sinus tracts (especially tunnels that allow pus and inflammation to escape). The diagnosis of DSC in advanced stages is easy as these openings (sinus tracts) can be seen all over the scalp. In early stages, up close exam and use of a dermatoscope can prove to be extremely helpful.
As seen yesterday, early DSC is characterized on dermoscopy by large yellow dots, thin vellus hairs within the area, broken hairs and healing (covered) or open sinus tracts. This picture shows a healed sinus tract (arrow).
This article was written by Dr. Jeff Donovan, a Canadian and US board certified dermatologist specializing exclusively in hair loss.
Dissecting cellulitis (DSC) is a rare scarring hair loss condition. It is characterized by deep inflammation and leads to the formation of draining sinus tracts (especially tunnels that allow pus and inflammation to escape - see number 1 and 4 in the picture). The diagnosis of DSC in advanced stages is easy as these openings (sinus tracts) can be seen all over the scalp. In the early stages an up close exam and use of a dermatoscope can prove extremely helpful.
Early DSC is characterized on dermoscopy by large yellow dots, thin vellus hairs within the area, broken hairs and healing (covered) or open sinus tracts. The early stages of the nodule can mimic alopecia areata (see top right, number 3 and 5). A swiss cheese like appearance is common as scarring progresses (number 2). Biopsies of DSC often show deep inflammation but in more advanced cases show inflammation higher up in the skin which can easily be mistaken for another scarring alopecia known as "folliculitis decalvans." Therefore, it is not uncommon for patients to be referred with a diagnosis of biopsy "proven" folliculitis decalvans only to need to explain to them after examining their scalp that what they actually have is DSC.
This article was written by Dr. Jeff Donovan, a Canadian and US board certified dermatologist specializing exclusively in hair loss.
Most hairs on the scalp are 70-85 micrometers in diameter. During the process of several hair loss conditions, the diameter of the hair shaft reduces. For example, reduction in hair shaft diameter can be seen in androgenetic alopecia, as well as conditions such as traction alopecia and alopecia areata. In genetic hair loss, a hair that is originally 80 micrometers becomes 60 micrometers and then slowly over years finds itself at 20.
Once a hair follicle thins below 55 micrometers I consider labelling it a "miniaturized" hair.
There is a big difference between a "miniaturized" hair vs "miniaturization". If a hair is 55 micrometers or less and most neighbor hairs are 80 micrometers - we say that hair is "miniaturized." However there is no real "miniaturization" of hairs. One can not really tell if a hair 65 micrometers is thinner from a natural process or from androgenetic alopecia. (Maybe it was just genetically set out to be 65 micrometers). However if none of the neighbouring hairs are thinner, there is less than a 0.05 % chance that it is thinner from early androgenetic alopecia. However if well over 20 % of the neighbors are thinner, there is a 99.5 % or more chance in males this is from androgenetic alopecia. In this case there is a miniaturized hair present and there is also miniaturization.
This article was written by Dr. Jeff Donovan, a Canadian and US board certified dermatologist specializing exclusively in hair loss.
Frontal fibrosing alopecia (FFA) is a type of scarring hair loss that occurs more often in women than men. It causes hair loss along the frontal hairline as well as several other areas including the sides and back of scalp, eyebrows, eyelashes, and body hair.
This picture shows a very typical appearance of the frontal scalp in FFA. There are numerous single hairs, many with scale around those hairs (called perifollicular scaling). A few broken hairs are seen and one hair in the picture is markedly twisted (a phenomenon known as "pili torti"). This is mild scalp redness.
Many treatments are available as we have reviewed together previously. This patient was started on a 5 alpha reductase inhibitor (finasteride, 5 mg) along with pimecrolimus cream (Elidel) and steroid injections. Clobetasol proprionate shampoo (Clobex) will be used weekly and reassessment will be done in 4-6 months.
This article was written by Dr. Jeff Donovan, a Canadian and US board certified dermatologist specializing exclusively in hair loss.
Discoid lupus erythematosus (or simply “DLE”) is a scarring hair loss condition. DLE has a unique feature that is important to know about: the early and aggressive treatment of hair loss in patients with DLE can often lead to some degree of hair regrowth. (This remarkably potential for regrowth can also be seen in some patients with two other scarring alopecias: frontal fibrosing alopecia and dissecting cellulitis).
This picture shows some of the classic features of early DLE. There is some redness admixed with a dirty brown pigmentation. Some white scale is seen. The arrows are pointing to one of the more important trichoscopic features: plugged hair follicles (also called “follicular plugging”). A large number of single hairs are seen indicated of its destructive potential.
This article was written by Dr. Jeff Donovan, a Canadian and US board certified dermatologist specializing exclusively in hair loss.
We will continue our discussion of how hair follicles change during the course of androgenetic alopecia (male pattern balding and female androgenetic alopecia). In general, hair follicles become thinner during the course of genetic hair loss. Before the onset of hair loss, most hairs in the scalp are thicker "terminal" hairs. These are typically 60 to 80 micrometers in diameter.
During the thinning process, terminal hairs become "miniaturized" hairs and eventually "miniaturized" hairs become "vellus" hairs. Vellus hairs are always less than 30 micrometers in diameters. During the course of balding, terminal hairs become less common and vellus hairs become more common. During advanced balding, vellus hairs outnumber terminal hairs in the areas of balding. In such a case, we say that the terminal to vellus ratio (T:V) ratio is much less than 1:2.
This article was written by Dr. Jeff Donovan, a Canadian and US board certified dermatologist specializing exclusively in hair loss.
It is often said that miniaturization of hairs (progressive thinning of hairs) is a main feature specific to men and women with androgenetic alopecia. This is not entirely accurate.
Miniaturization can be seen in many conditions including traction alopecia (shown here), alopecia areata as well as androgenetic alopecia.
This article was written by Dr. Jeff Donovan, a Canadian and US board certified dermatologist specializing exclusively in hair loss.
It is often said that the "miniaturization" of hairs (ie the progressive thinning of hairs) is a key feature specific to men and women with androgenetic alopecia. However, this is not accurate.
Miniaturization can be seen in many conditions including traction alopecia, alopecia areata (shown here) as well as androgenetic alopecia.
This article was written by Dr. Jeff Donovan, a Canadian and US board certified dermatologist specializing exclusively in hair loss.
There are various phases of the hair growth cycle that you may have heard of such as anagen, catagen and telogen. Anagen is the growing phase. Catagen is the transitional phase. Telogen is the resting phase where hairs stop growing. At the end of the telogen phase, hairs shed from the body- and end up in our brushes, combs, and shower drains.
So what is the "exogen phase"? Well, for years it was thought that once a hair is ready to be shed, it simply leaves that scalp when a hair underneath pushes it out. We know now that is untrue. A hair can of course leave the scalp when enough tug is given to it. However, the departure of a hair from the scalp is now recognized to be a highly regulated process which is known as "exogen." Therefore, hairs are not simply pushed out of the scalp - the process is tightly regulated.
This picture shows the scalp of a patient with a telogen effluvium (hair shedding disorder). Upright regrowing hairs (URG) are seen. In addition, a telogen hair (also called a club hair) can also be seen. This hair has officially been shed from the patient's scalp. It is nested amongst the existing hair. At the time of the next patient's next shampooing or brushing it will likely be removed completely from the scalp.
This article was written by Dr. Jeff Donovan, a Canadian and US board certified dermatologist specializing exclusively in hair loss.
