I posted an answer to a new question on Realself.com
Miniaturized hairs: do they grow same length as original hairs?
I posted an answer to a new question on Realself.com
Hair loss often occurs in women who start and stop birth control. This typically occurs 1-2 months after starting and stopping and can last 4-5 months. For some individuals it lasts 9-12 months.
For the vast majority of individuals, the abnormal shedding eventually stops and returns to normal shedding patterns- even without treatment. However, some women (small minority only) develop a chronic shedding pattern for an extended period of time and some notice that density does not make it back fully on account of an acceleration of underlying androgenetic alopecia.
In summary, most women will experience additional hair shedding for a few months after starting and stopping birth control. The excessive shedding will eventually slow and return to normal for most. Consultation with a dermatologist is advised if shedding persists after 6 months.
In the early stages of androgenetic alopecia (first few years), miniaturized hairs grow almost the same length as original hairs (not quite but close).
As time passes, and if androgenetic alopecia progresses, them miniaturized hairs grow in the scalp for shorter and shorter periods. In advanced cases, hairs affected by androgenetic alopecia grow for only a 2-3 months - and are very, very short and very, very thin. We call these "vellus-like" hairs rather than miniaturized hairs but they are a type of miniaturized hair. Over time, vellus like hairs just don't grow any more.
The Hair Pull Test: 3 is abnormal
Telogen effluvium is a form of hair loss where patients experience increased daily hair shedding. Instead of losing 40 or 50 hairs per day, patients with “TE” lose 80 to up to 600 hairs per day. A ‘pull test’ has traditionally been one of the methods that hair specialists are taught to perform when examining the scalp. To perform the test, 60 hairs are lightly grasped between the thumb and index finger and gently pulled upwards. Removal of more than 10 % of the hairs in the bundle (i.e more than 6 hairs) has been traditionally viewed as a positive pull test.
McDonald and colleagues from Ottawa, Canada performed a study revisiting this issues of what exactly constitutes a normal pull test and what limits should be set for abnormal. They studied 181 otherwise healthy individuals. The authors showed that for the vast majority of individuals, a pull test of 60 hairs extracts 0,1 or 2 hairs (97 % or more have 2 or less). The average was 0.44 hairs indicating that many individuals have no hairs removed. Interestingly, the date the patient last washed their hair, did not influence the pull test result nor did the frequency of brushing the hair.
This is one of my favourite studies of the year. It is simple and elegant and answers a lot important questions. I have long abandoned the “6 hair rule” for the pull test, and frequently have told the dermatology residents and trainees that work with me that even a few hairs coming out is abnormal. I’m grateful for this well conducted study and it has renewed my interest in the pull test.
McDonald et al. Hair pull test: Evidence-based update and revision of guidelines. Journal of the American Academy of Dermatology 2017; 76: 472
I posted an answer to a new question on Realself.com
I posted an answer to a new question on Realself.com
Every now and then, I share a landmark study which has the potential to change the way we think about the hair follicle, and how it grows. Today is one of those days.
Researchers at the University of California San Francisco reported last week an important new finding: without specific immune system cells called T regulatory cells (T regs), hair follicles do not grow properly. The study was performed in mice, but likely has relevance to humans.
T regulatory cells are important immune cells. Mice have them and so do humans. These immune system cells act as sort of peacekeepers of our immune system. In scientific terms, we say that these cells play a key role in ‘immune tolerance.’ They tell other immune cells of our body to stay quiet when the time is right to stay quiet and this helps prevent unnecessary allergies and autoimmune diseases. To study the role of T regulatory cells, the researchers developed a clever mouse model whereby T regulatory cells could be removed from the mouse whenever desired. In these studies, mice were shaved of hair and hair regrowth patterns were observed. Surprisingly, hair did not regrow after shaving.
There has now been a shift in thinking. Hair follicle stem cells, at least in mice, appear to listen to the commands of T regulatory cells to know when to grow – and when to stay quiet. Tregs are now understood to accumulate around hairs at the end of the hair growth cycle (in the telogen phase) and help direct hair follicle stem cells to make a new hair. Without Tregs, the growth phase (anagen phase) does not begin. This information could have direct relevance to humans and our understanding of a variety of hair loss conditions. It is well known from previous studies for example, that many of these genes that contribute to the condition alopecia areata are in fact genes that regulate T regulatory cells. In addition, other studies have shown that by supporting T regulatory cells in their functioning, it is possible to can help regrowhair in alopecia areata.
Reference
Ali et al. Regulatory T Cells in Skin Facilitate Epithelial Stem Cell Differentiation. Cell 2017.
I posted an answer to a new question on Realself.com
I posted an answer to a new question on Realself.com
I posted an answer to a new question on Realself.com
I posted an answer to a new question on Realself.com
I posted an answer to a new question on Realself.com
I posted an answer to a new question on Realself.com
I posted an answer to a new question on Realself.com
One of the top 50 questions I am asked is whether biotin supplements should be used. The short answer is really that there is no good evidence that biotin does much for most people. It is however, quite safe and overdosing is unlikely provided one sticks to 5000 mcg or less per say.
Is anyone biotin deficient?
However, the following groups may be more likely to have biotin deficiency:
1. individuals with intestinal issues,
2. women who are pregnant,
3. individuals taking anti-seizure medications, chronic antibiotics, or isotretinoin
4. individuals who consume alcohol chronically
5. those with inborn errors of metabolism
6. the elderly
7. those with extremes of poor diet
In those who are recommended to take biotin, type of biotin supplement does not appear to matter. 1000 mcg twice daily to up to 2500 mcg is appropriate dosing for most. Once should never exceed 5000 mcg. I always advise individuals to review this question with their physician an avoid unnecessary supplementation.
I posted an answer to a new question on Realself.com
I posted an answer to a new question on Realself.com
There are many causes of eyebrow hair loss and each has it's own treatment. Too often patients rush to treat their eyebrow loss without pausing to ask "What exactly is my diagnosis?" Here are a few common reasons for eyebrow loss and their treatment.
If the eyebrow loss is due to age related changes or over plucking/tweezing the options inlcude
a. Minoxidil
b. Bimatoprost (Latisse)
c. Hair transplantation
d. Tattoos, and microblading
If eyebrow hair loss is due to the autoimmune disease alopecia areata, a majority of patients will also have evidence of aloepcia areata at other areas (scalp, eyelashes). Treatments for eyebrow loss due to alopecia areata include:
a. steroid injections b. topical steroids c. minoxidil
d. bimatoprost
e. oral immunosuppressives (Prednisone, methotrexate, tofacitinib
f. Tattoos and microblading can also be used.
Frontal fibrosing alopecia of the eyebrows is certainly the most underdiagnosed cause of eyebrow hair loss in women who first notice eyebrow hair loss in their late 40s and early 50s. Hair transplants are ineffective in most, if not all patients with active disease. Treatment options for FFA of the eyebrow include:
a. steroid injections and topical steroids b.topical non steroids (pimecrolimus cream)
c. oral finasteride
d. oral hydroxychloroquine, oral tetracyclines
e. Tattoos and microblading can also be used.
Trichotillomania is common and 3-5 % of the world pull out their own eyebrows due to underlying psychological factors. For some, the pulling is temporary and for others is a chronic condition. Treatment of the underlying psychological factors (stress, depression, anxiety, obsessive compulsive disorder) can lead to improvement. Hair transplants are not an options if the patient is actively pulling his or her eyebrows
Dozens of other causes of eyebrow loss are also possible including a variety of infectious, autoimmune and inflammatory conditions. Consultation with a dermatologist or hair transplant surgeon is recommended. I strongly advise consulting a dermatologist before proceeding to hair transplantation for women over 40 with new onset eyebrow hair loss after age 40.
Nails are sometimes important to examine in patients with hair loss. Some autoimmune diseases produce changes in the nail plate and some produce changes in the very tiny blood vessels of the nail fold (see arrow).
Three diseases in particular are associated with changes in the tiny vessels of the nail fold - dermatomyositis, system lupus erythematosus (sometimes just called "lupus") and scleroderma. All three of these diseases can cause hair loss and may be associated with more serious internal illnesses.
I don't perform nail capillaroscopy in all my patients. However, if the patient's story has any suggestion of autoimmune association, I often perform a nail bed capillaroscopy.
