Features of androgenic alopecia in men

Male androgenic alopecia, also known as male pattern baldness is an androgen dependent disorder seen in genetically predisposed individuals (1).

Male AGA is seen in all ethnicities

• the highest prevalence is seen amongst the Caucasians with around 80% of men aged over 70 years having AGA
• in Asians the reported prevalence is 47-60% in males older than 70 years
• older studies report that balding in African-American men is four times less common than compared to Caucasians (2)

The frequency and severity increases with age in every population (2)

Genetic factors predisposes to AGA

• the current scientific data suggest that AGA is a polygenic disorder
• there are strong concordance rates of between 80% and 90% for monozygotic twins
• risk of developing AGA is greatly increased in men with a father suffering from AGA than in men with a non-balding father (2)

Although AGA is androgen dependant, almost all men with AGA have a normal circulating androgen level

• it is thought to be due to increased androgen receptor density and/or increased activity of 5-alpha-reductase type II in genetically predisposed hair follicles (2)

Reference:

• 1. Olsen EA et al. Evaluation and treatment of male and female pattern hair loss. J Am Acad Dermatol. 2005;52(2):301-11
• 2. Blume-Peytavi U et al. S1 guideline for diagnostic evaluation in androgenetic alopecia in men, women and adolescents. Br J Dermatol. 2011;164(1):5-15.