Month: September 2011

I know that you’ve addressed this before in a post a few years ago, where you suggested that exclamation mark hairs were a sign of a more serious infection. However, I was wondering if you could provide a little more information as to if it is also a sign of Is it a sign of traditional male pattern baldness?

Particularly if the thinning is very gradual down the hair shaft, only detectable if you bend the fallen hair so as to compare the top of the hair with the bottom next to the bulb.

If they get thinner towards the bulb and less heavily pigmented is this an example of the process of miniaturization? If not, rather than an underlying infection, could it be due to a lack of vitamins, or telogen effluvium?

If this smaller diameter is noticeable on all the hairs that are being lost, even from the side and back of the head, or even body hair is that the case where it is more likely to be as you originally suggested an underlying infection?

Hairs that look like exclamation marks can be a sign of a variety of issues, but alopecia areata is chiefly among them and often points to this diagnosis. Other possibilities include lupus, thyroid disorders, and some allergies. I don’t mean to get you alarmed, so see a doctor for an examination to get to the bottom of the problem.

I’ve written about this before — Is Hair Normally Thinner Towards the Root?.

Snippet from the article:

Stand up straight! And do something about that hair!” Annoying? Sure. But such parental advice may have made humans what we are today. Because our upright stance, and relative lack of hair, may have enabled our human ancestors to run far and fast enough to capture their prey. So say scientists in the Journal of Human Evolution.

The idea that standing on two legs and shedding all that body hair might have helped early humans keep cool on the African savanna was first trotted out in the late 1980s. But those early models had our ancestors standing still in a gentle breeze. Scientists simply didn’t have the computational power to assess what might happen when those early humans had to up and chase down a meal.

Read the rest — Upright and Hairless Make Better Long-Distance Hunters

The above article is actually a transcript of a podcast. The published model can be found here.

Hi Doctor,

I know everyone is genetically different in their balding patterns, speed, etc. but how long does it generally take for miniaturization to turn a healthy hair folicle into one that can’t grow any hair? Weeks? Months? Thanks!

You are right — everyone is different. The hair you see on top of your head reflects about 1/2 inch per month of growth. Miniaturization can take months or possibly even years to appear.

Is it true that human hair has a predetermined number of cycles? If someone experiences TE or chronic TE are they using those cycles prematurely and causing their hair to thin earlier than it would have?

It is true that life of a hair determines the number of hair cycles you will have. I was bald in the crown by the time I was 45, so my hair there died… and then I had transplants to correct it.

If your hair cycle (from telogen to anagen) is 3 years and you have 10 cycles genetically programmed for that hair, then that hair will die at the age of 30. Although I am making this example sound simple, it is certainly not that simple… but male pattern baldness does probably follow that rule. I do not believe that telogen effluvium changes the hair cycle’s length, but just the telogen phase of that cycle.