Dr. Charles J. Doillon & Clement Beaumont

 

Controversy has persisted for some time now over the very existence of an area in the hair follicle termed the bulge. Based on new research surrounding the relationship between the bulge and the bulb and by adapting certain techniques, electrolysis treatments may become more effective with less re growth.

 

The existence of the bulge has been scientifically demonstrated and advanced research has provided new insight on the hair follicle regeneration process over the course of a hair growth cycle. Based on this new data, studies were undertaken in a research centre in Quebec in order to observe microscopic lesions on human follicles following electrolysis.

 

The hair follicle undergoes repeated cycles of growth periods (anagen), regression (catagen), and rest (telogen) throughout our life.

 

Along the cycle, a specific area has been identified – termed the bulge, situated close to the sebaceous glands, at the limit between a permanent hair (upper portion) and transient hair (lower portion), and close to the insertion of the arrector pili muscle to the hair follicle.

 

Recently, the bulge has been the focus of advanced studies by scientific experts, since it was believed to host the stem cells and progenitor cells of the epidermis and skin appendages (hair follicle, sebaceous and sudoriferous glands). These cells were found to occur in the outer root sheath within the bulge area.

 

During the follicle growth cycle, the stimulation of stem cells in the bulge leads to the migration and differentiation of progenitor cells toward the epidermis, the sebaceous gland, and specifically towards the hair bulb. They differentiate into a variety of epidermal cells, and form the cells of the bulb during the onset of the newly-formed anagen follicle. These cells extend down into hair-follicle matrix cells during the descent of the newly formed bulb. The bulge therefore plays a role in the life cycle of the hair follicle, when conditions are suitable.

 

Demonstrating this was made possible by using genetically engineered rodents in which a fluorescent green probe is introduced into the genetic material of most cells and then transferred by hair follicle transplantation into non-fluorescent animals. It was observed that fluorescent cells were concentrated in the bulge area during telogen and early anagen phases. Then, in the late anagen phase, the fluorescence was found concentrated in the bulb.

 

The stem cells of the bulge region are normally quiescent throughout the catagen, telogen and most of the anagen phase, but proliferate briefly at anagen onset. We can see from this the pluripotent character of these stem cells emerging from the bulge.

 

In the bulge, the progenitor cells migrate at the onset of the anagen phase and their proliferation is intensely stimulated (the highest proliferation rate of any mammalian tissue). The bulge most likely controls the life cycle of their hair follicle. However, this phenomenon requires the presence of connective tissue cells (mesenchymal cells in the dermis near the hair follicle) and the formation of capillaries or micro vessels by endothelial cells (angiogenesis). These two types of external cells set off the reproduction of progenitor cells and their differentiation into specialized cells to form the new bulb, regenerating the lower follicle at the onset of a new follicular cycle in adults.

 

Based on this new insight of hair follicle development, we should logically target two areas of the hair follicle: the bulb and the bulge. But there is a problem.

 

Stem cells at rest in the bulge area are more heat-resistant than progenitor cells and are therefore harder to destroy. It would be more appropriate to target migrating progenitor cells (moving down the outer root sheath) located between the bulge and the bulb, as well progenitor cells located in the bulb itself (in the inner sheath). The reproduction and differentiation of these cells is very active in these skin surface, thereby increasing the risk of superficial epidermis burns.

 

For the other phases of the hair cycle, the application of this new data appears to differ. Thermolysis applied to a hair follicle in the telogen phase will directly target the stem cells and progenitor cells, but may require a greater amount of energy (considering their resistance to heat) which can be provided by an insulated probe (heat concentration at the tip). It is difficult to determine if a follicle in the catagen phase would be easy to destroy however, given the presence of the two types of cells: those in the catabolic state (which will be destroyed since they cannot withstand heat and the stem cells at rest in the bulge area (which will be heat resistant).

 

Is it still difficult to predict with any certainty if a hair follicle will regenerate or not after treatment. But thanks to this new data and ongoing research, we are now better able to understand what can be modified to improve electrolysis treatments, and these latest results already represent an exceptional breakthrough in terms of insertion techniques.

  Dr. Doillon has received scientific and medical awards, research grants and is an author and co-author of several scientific publications.  Clement Beaumont is President of Dectro International.  www.hairroute.com

By Geoffrey P. Redmond, M.D.

Dear Dr Redmond: I've read about polycystic ovary syndrome (PCOS) but what else can cause hirsutism? From what I've read about it, many of the women I treat do not seem to have PCOS.

You are quite right; PCOS is not the only cause of hirsutism. PCOS is the cause that has received the most attention, so medical articles often give the impression that this is the only cause. But there are several others. The best way to explain these is to review the steps in the process which leads to increased hair growth, and consider what can happen at each step to cause the increase.

So-called "sexual hair" grows in response to androgens - the so-called "male hormones." This term is a little misleading because women have active levels of androgens in their blood, just as men have estrogen in theirs. Testosterone is the most active androgen, but there are several others such as androstenedione and DHEA. (DHEA is usually measured as the closely related form DHEA-S.) Androstenedione and DHEA them-selves do not affect hair growth but they are converted by the body to testosterone, which does.

Both the ovary and the adrenal gland release testosterone. If the blood level of testosterone is elevated, it is important to find out whether it is coming from the ovary, or the adrenal, or both. We cannot generalize, but need to do tests to see which is the source.

The best test for determining where the testosterone is coming from is the dexamethasone suppression test. Dexamethasone (similar to cortisone) is given for about a week to suppress the adrenal. Any testosterone remaining in the blood at the end of the test must be coming from the ovary. For example, if the testosterone is 75 before the test and 60 at the end of it, most of the testosterone is coming from the ovary. But if the post-test value is 15, most of the testosterone is adrenal in origin.
Now, let's consider polycystic ovary syndrome again. (An older name for this, still used sometimes, is Stein-Leventhal syndrome.) This is often the diagnosis when the ovary is the source of the extra testosterone, and this is where much confusion enters in. PCOS is polycystic ovary syndrome (a collection of features of a medical condition) usually defined as oligomenorrhea (infrequent periods), anovulation (failure of the ovary to release an egg cell), obesity and hirsutism. The extra weight tends to be on the upper body with the hips and legs usually being thin.

Regular readers of this column are aware that I do not like the term "poly-cystic ovary syndrome." One reason is that it scares patients, often unnecessarily. The other reason I don't like labeling women as having PCOS is that most affected women have only some parts of the syndrome. If a woman does have all the features listed above, it is reasonable to make the diagnosis of PCOS. If she has only some, it is better to term her condition "ovarian androgen excess."

I do need to add that women with PCOS, who are overweight, are often associated with insulin resistance and diabetes. When high testosterone levels seem to begin at or after menopause, the cause is often a condition called thecal cell hyperplasia. The theca cells are in the ovary and. make testosterone. The cause of this is unknown; it may be a late form of PCOS.

Sometimes a woman has ovarian androgen excess but lacks most of the features of PCOS - a situation for which there is no specific term. The same is true when the testosterone comes from the adrenal. The term "late onset adrenal hyperplasia" simply means that the adrenal is not making its hormones in the right proportions. There are severe hereditary forms, which are usually present at birth. Some forms have specific lab-oratory abnormalities that will con-firm the diagnosis, but in mild cases the tests are not specific. This means that a small number of adult women with hirsutism have this so-called late onset adrenal hyperplasia. But for the common, milder forms, this term is not really appropriate.

So, just as we are left with ovarian androgen excess as a diagnosis, we also have adrenal androgen excess. These terms are not very specific but I prefer them because they don't imply that a woman has a more severe disease than she really has.
Now I need to add a third source of hirsutism besides the ovary and adrenal. This is the hair follicle itself. Some people have follicles that are so sensitive to testosterone that even nor-mal levels stimulate them. In fact, this is by far the most common reason for increased hair growth in women. Women with sensitive follicles do not have a hormonal disorder at all. Their ovaries and adrenals are working fine.

So this is the not-entirely-satisfying state of affairs with hirsutism diagnosis.

Dr. Redmond is president of the Foundation for Developmental Endocrinology, in Cleveland, Ohio, and author of the book The Good News About Women's Hormones. Questions for Dr Redmond should be mailed, faxed or e-mailed to: International Hair Route, 106 Lakeshore Road East, Suite 212, Mississauga, ON, Canada L5G 1E3. Fax (905) 271-9748.

Reprinted from INTERNATIONAL HAIR ROUTE, vol. 42, February 2000