Current Views on the Pathogenesis of Patterned Hair Loss

Patterned hair loss, the most common type of hair loss affecting men an women, is characterized by a process of progressive hair miniaturization whereby large, pigmented terminal hairs are replaced by fine, colorless vellus hairs (1,2). In men, this condition preferentially affects hair on the superior and anterior temporal areas of the scalp, whereas in woman it more commonly presents in a diffuse pattern in the crown, with or without sparing of the frontal fringe (3,4).

In unaffected scalp, hair has a normal, healthy life cycle of anagen phase of two to six years, catagen phase of two to three weeks, telogen phase of two to three months (5). The key point in patterned hair loss is progressive shortening of anagen phase. Since there is less time to grow, hairs become shorter and finer, to the point where individuals appear to be bald, despite the continuing existence of large numbers of fine vellus hairs (6,7)

Androgens play a central role in this process of miniaturization, hence the reason both male pattern hair loss (MPHL) and female pattern hair loss (FPHL) are collectively referred to as androgenic or androgenetic alopecia. MPHL appears to result from a combination of hyperandrogenism, an androgen-dependent genetic predisposition to androgen sensitivity and an androgen-independent genetic predisposition to androgen sensitivity. (8).

The Role of Androgens in Female Pattern Hair Loss

The influence of androgens in FPHL is not pronounced as in MPHL. Certainly, women with clinical hyperandrogenism- identified by the development of acne, hirsutism, and oligomenorrhea- frequently develop a pattern of hair loss similar to what is seen in males, with deep bitemporal recession and vertex thinning. Similarly, those with androgen-producing tumors develop male pattern of thinning. However, the majority of women with FPHL show no clinical signs of hyperandrogenism and have normal testosterone and dehydroepiandrosterone sulfate (DHEA-S) levels (33,35).

Explanations for the more limited androgen role in females have focused on the enzyme aromatase, which has a scalp concentration fivefold higher in females than in males. Aromatase catalyzes the conversion of testosterone and androstenedione to the estrogens, estradiol, and estrone, respectively (16). It has been proposed that these estrogens modulate hair loss by increasing the levels of sex hormone binding globulin (SHBG), a serum protein that binds androgens, and in doing so decreases the amount of bioavailable hormone. This theory is congruent with the studies demonstrating an inverse correlation between sex hormone binding globulin levels and the degree of hair loss in women (36)

In addition, aromatase may blunt the impact of androgens by decreasing tissue levels of DHT, via the metabolism of androstenedione, a precursor hormone to DHT (37). Lending support to the important role of aromatase is the finding that women treated with aromatase inhibitors experience FPHL as a side effect (21).

Genetic Factors

The mode of inheritance of FPHL is unknown. Women with FPHL have almost more than twofold male first degree relatives having with androgenic alopecia comparing to their female first degree relatives (38). In any case, the inheritance of FPHL, like MPHL, is probably polymorphic in nature. Interestingly, the development of polycystic ovary syndrome (PCOS) and MPHL is predicted by the same variation of the CYP17 gene on chromosome 10q24.3, which suggests that PCOS may be the female phenotypic expression of MPHL (39,40)

The Incidence and Degree of FPHL at Various Ages in Women

The incidence of female pattern hair loss (FPHL) is more difficult to establish than in men and its diagnosis is more challenging. This is because of less obvious patterns of hair loss than in men and because of the frequency with which other type of hair loss occurs. In brief, it is “the great mimicker” and should be included in the differential diagnosis of diffuse hair loss in any woman. (6).

Three frequently occurring patterns of hair loss have been described in women:

1. A more or less “male pattern” or “fronto-parietal pattern”

Hamilton examined 214 women in his study and found at least Type II MPB in 79% of them after puberty. He noted, however, that the bi-temporal recessions seen in Type II tended to be less prominent in women than in men and was likely to go unnoticed until their late twenties. Type IV MPB occurred in 25% of women by the age of 50 years and 50% had Type IV by the age 60 years. Type IV was defined as consisting of (i) deep fronto- temporal recessions extending more than 3 cm posterior to a coronal plane between the external auditory meatus and (ii) some mid-frontal hairline hair loss. (7)

2. Centrifugal Pattern

A “centrifugal pattern” of hair loss first discussed by Ludwig (8): it consisted of hair loss over the caudal scalp. In contrast to Hamilton, he emphasized the essentially intact frontal fringe in these individuals. This type of hair loss arbitrarily divided in to three degrees of severity as shown in Fig. 2B2-4b. Postmenopausal women shoved an increased tendency to a more male pattern of hair loss.

3. Christmas Tree

A “Christmas tree” pattern first described by Olsen (9) (Fig. 2B2-5a and b). She noted that women with hair loss did not necessarily present with diffuse hair loss over the entire vaultal scalp, but instead may have increasing hair loss toward the frontal scalp “with encroachment on and sometimes breach of the frontal hair line”.loss.

Four other characteristics of patterned hair loss in women are important to hair restoration surgeons

1- Such women also frequently have or may eventually develop decreased hair density in temporal, parietal, and occipital areas that are normally used as donor areas for transplanting. Therefore, they may or may not be acceptable candidates for transplanting (11).

2- Many of these women develop small (2 to 5 mm) oval irregular shaped areas of total alopecia that are scattered within the areas of diffuse thinning. Such areas can be punched out and then sutured or transplanted with a mixture of two-to three FU (11).

3- In women, there appears to be two main peaks of onset of pattern hair loss: the third and fifth decades. Those having earlier onsets tend to develop more severe degrees of hair loss and this should be borne in mind when a decision is made about treating women in their late teens or twenties (6)

4- Norwood also believes that androgen-dependent MPB is a different disease than FPHL. In his study he found that FPHL begins in the late twenties and peaks after 50 year of age when testosterone levels are falling, suggesting that it is not an androgen dependent. Birch et al. also have written that evidence exists for FPHL being either androgen dependent or androgen independent in different individuals. They summarized their view of the condition as follows: “Female pattern hair loss and it is possible that both androgen-dependent and androgen- independent mechanisms contribute to the phenomenon” (16).


Medical Treatment Options & My Personal Way of Describing the Course of Medical Treatment

Before we start medical treatment, it’s very important that the patient is well informed about the course of this progressive-genetic hair loss/miniaturization, the length and frequency of the medical treatments; otherwise patients generally quit few months after the start of therapy mentioning that the therapy he/se has given was not effective and even might blame physician to be a trades man to sell therapies to the patients.

The best way to prevent misunderstandings and future problems regarding the effectiveness of the therapies that you have advised is thorough information. So how I do it;

First step: Description of FPHL in a simple way by giving ‘water tank with a hole on the bottom’

We can assume the scalp like a tank filled with water with a hole on the bottom. Tank represents the scalp and the water in it represents the existing hairs. I tell my patients that, there exists a hole on the bottom of their tanks coming genetically where there is no way to close and continue telling that this hole’s size may vary accordingly to genetic tendency and their stress levels -which clears why the hair fall tends to peak time to time- and continue to tell that, their tanks will leak all the time and best treatment to keep and increase the water level is keep adding water from outside. I also resemble the medical treatments like a fuel that we put in to our car’s tank where we need regular refueling. After this point they most likely understand that there is no miracle treatment which will cure their problem when applied few times and convince to have these treatments regularly.

hair transplant
Second Step: Simple Classification of current medical therapies.

Here is the exact way how I describe & simplify the treatment options for my patients. I group the treatments under three main headings:


2-Laser therapy

3-Injection treatments

Prescription Includes

    • Minoxidil solution
    • Shampoos, lotions
    • vitamin tb s

Laser therapy:

    • Low Level Laser Therapy

Injection Therapies includes:

    • PRP
    • Growth Factor
    • Hair Filler
    • Acell




Male & Female Pattern Hair Loss, Chapter 2; Hair Transplantation 5th Edition by Walter Unger


-My personal contribution which briefs about The Explanation Strategy of Female Pattern Hair Loss Course & Medical Therapy Options Classification to the patients.


What my patients say

I am Airat Khalirakhmanov. I am the head of the Surgery Department of the health-care unit of the Kazan Federal University. In November 2019, I attended an internship with Dr. Sezgin. He met me very good-naturedly and showed me all the details of the work in his clinic. He thoroughly performed the operation for hair transplantation, showed me all essential details and what we need to pay special attention during the surgery. This was a great discovery for me. He showed new opportunities, new horizons in hair transplantation. The level of his performance impressed me very much. A lot of things, that I saw in Dubai, in his clinic, amazed me. Therefore, I highly recommend contacting Dr. Sezgin like a master of your craft. I really liked what I saw and how it's done and it struck me from a professional point of view of hair transplantation. In addition, the doctor is a very good-natured and helpful colleague, so I highly recommend him.

Airat Khalirakhmanov
Hair Transplant Surgeon

Assalam u alaikum Dr. SezginThank you so much for examining and dedicating precious time to me.I saw your work on Insta. You are really an Artist.Once again thank you so much for valuable suggestion and time.Nice to meet you. Allah Bless you.


I have done an FUE hair transplant with Dr Cagatay SEZGIN; I m pretty happy with the amazing result. My hair looks dense, natural and smooth even people can not tell the difference. Now I understand very well why they call him as ‘celebrity hair transplant surgeon’I highly recommend Dr Sezgin to anybody who’s planning to have hair transplant in Dubai. Wish you all my best doc! 

Ali Alaskar
Emirates Airline Captain Dubai

I had the pleasure of doing a hair transplant with Dr C SEZGIN  I can only say good thing about Dr Sezgin and the clinic. Dr. Sezgin took personal time to explain the surgery and helped me make my decision. I felt comfortable with him because contrary to many others HE SPECIALIZES IN HAIR AND HAS DONE SO FOR 20 YEARS. He also is a full time in Dubai and has a lovely clinic which helped me feel safe in case of any post-operative care.I can only praise Dr. Sezgin. He is very competent, very flexible and very friendly. One can feel his experience by his confidence. His staff are great also, some of them having been with him for years. They make a great team and can’t praise them enough.

D. B.
Airline Captain Dubai
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