is a theory floating around that dihydrotestosterone (DHT) stimulates
apocrine sweat glands to produce uric acid. Via the sebaceous glands,
the uric acid drains to the bottom of the hair follicle and cornifies
the sides of the hair follicle and this restricts the transfer of
nutrients from the bloodstream to the hair follicle. Those hair follicle
portals for nutrients ultimately become sealed off resulting in smaller
hair follicles with each progressive cycle. There are several problems
with this theory.
First, the apocrine glands and hair follicles or sebaceous glands
are not physically connected. They are separate structures within
the skin. So for acid to come from the sweat glands and enter the
hair follicles it would have to come up onto the skin and then drain
into neighboring hair follicles. Thus if the theory was correct
then it would suggest that those that sweat a lot would have pattern
baldness or that sweaty areas would be most likely to develop hair
loss. Arm pit apocrine glands are very active but there is no hair
loss there so if the apocrine glands were contributing it would
have to be only those on the scalp that would be producing uric
acid and causing this alleged cornification. However, baldness is
not associated with those that are more inclined to sweat or are
more active or with exceptionally sweaty areas. If the theory were
true, it would also suggest that a cure for pattern baldness would
be to wash regularly and use deodorant!
Second, many studies have been done on pattern baldness where skin
biopsies have been taken and examined under the microscope. Despite
these numerous studies, no one has reported observing cornification,
thickening, or scarring of pattern baldness affected hair follicles.
Third, it would be impossible for hair follicle transplants to
work. The apocrine sweat glands would still be present on the top
of the scalp and still active. If new follicles were transplanted
to this area of uric acid production that allegedly cornifies hair
follicles then one would expect that the newly transplanted hair
follicles would also be affected. However, this is not the case.