Hair Flashcards
difference between telogen and anagen hairs
anagen are embedded deeper and do not come out very easily, 90% of total hair
telogen hairs are less anchored and come out easily
term for common baldness
androgentic alopecia
What causes adrogentic alopecia
large terminal follicles transform into small vellus follicles (visible hair to invisible hair)
due to action of Dihydrotestosterone
Describe the male pattern of baldness
frontotemporal and vertex thinning
–> loss of all hair except occipical fringe
Describe the female pattern of baldness
retain frontal hairlines but have decreased density on crown
difference in timing of male and female balding
males much earlier (10 years)
What should you do if you see male pattern baldness in a female?
check DHEAS and testosterone
**checking to see if she has androgens which would be driving the pattern of baldness
DHEAS = Dehydroepiandrosterone
Genetics of androgeni alopecia
autosomal dominant or multifactorial
drug that induces anagen or increases anagen duration to increase the hair density
Minoxidill (Rogaine)
in men, causes reversal of the minituration process and/or slows the progression of hair loss in androgenic alopecia
Minoxidil (Rogaine)
Who benefits most from the use of minoxidil (rogaine)
young men to stop progression of hair loss
and women with androgenic alopecia
inhibits type II 5 alpha reductase
propecia (finasteride)
**inhibits the conversion of androgen testosterone into dihydrotestosterone
Does propecia (finasteride work?
yes pretty well, but it causes sexual dysfunction that may NOT be reversible
How many hairs do you shed daily
100 hars
What is telegen effluvium
excess shedding of hair due to pre-mature shunting of anagen to telogen phase
–> 20-35% of scalp hair lost
When does telogen effluvium occur?
6 weeks to 3 months after precipitating cause
Does hair regrow after telogen effluvium?
yes, in 6 to 12 mos
*unless precipitating cause is not removed
What is the most common cause of telogen effluvium?
childbirth
What is the treatment for telogen effluvium?
reassurance–hair will grow back
can give 2% minoxidil solution
term for acute loss of 80-90% of scalp hair due to an extreme alteration of growth in the majority of anagen hair
anagen effluvium
What commonly causes anagen effluvium? When does it occur?
chemo drugs and anticoagulants –> occurs 1-2 weeks after cause
What is drug alopecia and how is it different than anagen effluvium due to chemo drugs?
drug alopecia presents as telogen effluvium or can be slow loss or thinning over years
-due to drugs that affect hair production
?? im not entirely sure what the distinction is other than time course and amount lost??
immunologically mediated hair loss + nail pitting
alopecia areata
describe the hair loss in alopecia areata
circular area of complete loss with a normal scalp