PEER-REVIEW | HAIR LOSS |


TREATMENTS FOR MALE PATTERN HAIR LOSS


Maria Bonnici reviews the current mainstream and alternative treatments for male pattern hair loss, including hair transplants, oral finasteride, and low-level light therapy


ABSTRACT Androgenic alopecia (AGA) or male pattern hair loss is the most common cause of hair loss in men, affecting 50% of men aged 40–49 years. A distinctive alopecia pattern is usually formed. Androgenic alopecia is influenced by both genetic and environmental factors such as inflammation, smoking, UV radiation, and other pollutants. The aim of this article is to dwell into the causes of AGA and into the current mainstream and alternative treatments of this common cosmetic disorder.


Caucasians with a lower prevalence in oriental races3


studies demonstrate a gradual increase in incidence with advancing age1,3–4


A .


AGA affects 50% of men between the ages of 40 and 49 years1. AGA causes significant psychological distress


and it is one of the most common reasons for dermatological consultations leading to newer modalities and treatments being researched for its cure5


. This article aims to look at the causes of AGA in men


and the current mainstream and alternative treatments for this common cosmetic disorder.


Classification In men, AGA develops with a distinctive patterned hair loss, but occasionally, men develop a female presentation, which has a less distinctive pattern. The most accepted method of classification is the modified Norwood- Hamilton classification which consists of seven groups and four specific different types of variants (Figure 1)6–7


.


Pathogenesis Hair loss is induced via activation of androgen receptors in hair follicles by dihydrotestosterone (DHT). In men, there is an elevation of type II 5-alpha reductase enzymes, which metabolise testicular testosterone in the blood to DHT8–9


18  .


NDROGENIC ALOPECIA (AGA) OR male pattern hair loss is the most common cause of hair loss in men and it is affected by genetic and environmental influences1,2


. It affects


all races but it is more common in . All


The binding of DHT to androgen receptors in hair


follicles leads to a progressive shortening of the anagen (growth) phase with a prolongation of the telogen (rest) phase of the hair follicles. This replaces thick, pigmented terminal hair into fine, non-pigmented vellus hair9


.


AGA is also influenced by environmental factors, that lead to follicular micro-inflammation and fibrosis10


. This


can be triggered by microbial toxins (related to Propionibacterium sp, Staphylococcus sp., Malassezia sp., or Demodex sp.), oxidative stress11


like seborrhoea. Unlike in scarring alopecia, this process is slow and indolent10 UV radiation14–15


. The ageing process, smoking12–13 , , and other pollutants may also play a role


in hair loss. All the above environmental factors lead to the formation of free radicals, which are no longer adequately scavenged by the cell’s defence mechanism resulting in damage to the hair follicles. AGA has a polygenic mode of inheritance16


and this is


established due to the high prevalence and the widely expressed phenotypes. The two major genetic risk loci are on the X chromosome (AR/EDA2R locus) and the PAX1/FOX A2 locus on chromosome 2016


.


Medical treatment Oral finasteride (Propecia, Merck Sharp & Dohme Corp., NJ) and topical minoxidil (Rogaine®, Johnson & Johnson Consumer Inc.) are the only two therapeutic agents approved to date by the Federal Drug Administration (FDA) and the European Medicines Agency (EMEA) for the treatment of AGA1


. January/February 2016 | prime-journal.com , and microscopic flora


MARIA BONNICI MD, Mater Dei Hospital, Mata, L-Imsida, Malta


email: bonnimar@gmail.com


KEYWORDS Androgenic alopecia, Finasteride, Minoxidil, Hair transplantation, Botulinum Toxin , Laser, Cell mediated treatment, Platelet rich plasma


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