85 - Androgenetic Alopecia Flashcards
Most common type of hair loss
Nonscarring progressive miniaturization of the hair follicle with shortening of the anagen pahse
Androgenetic alopecia
Most frequent clinical pattern in men with AGA
Recession of the frontal hairline, mainly in a triangular pattern, later followed by a vertex thinning with progression until the top of the scalp is completely bald
Hamilton-Norwood type
Most common type of AGA in women
Diffuse thinning of the centroparietal region with maintenance of the frontal hair line
Ludwig type
Diffuse centroparietal thinning similar to the Ludwig pattern with an additional breaching of the frontal hair line
Olsen type
Molecular studies have recognized _____ genetic regions associated with AGA
12
Androgen chiefly responsible for the follicular pathology
Probably acts primarily on dermal papilla, the predominant site of androgen receptor and type II 5alpha-reductase expression within the hair follicle
Dihydrotestosterone
The scalp skin usually appears normal in AGA, but frequently associated findings include
Seborrhea
Seborrheic dermatitis
Balding scalp examination should include checking for
Photodamage
Field cancerization
For the hair pull test (Saboraud maneuver), approximately _____ hairs are grasped between the thumb, index, and middle fingers from the base of the hairs near the scalp and firmly, but not forcelly, tugged away from the scalp
50 to 60
If more than _____% of the grasped hairs are pulled away from the scalp, this constitutes a positive pull test
10
A positive pull test confirms
Active hair shedding
In AGA, the hair pull test may be positive in the frontal region, while it is typically negative in the
Occipital region
Typical findings in AGA on phototrichogram
Reduced hair density in a pattern distribution compared to the occipital area
Anagen-to-telogen ratio is normal or decreased when comparing frontal or vertex to the occiput
The preferred area for biopsy is the
Central scalp in an area representative of the hair loss process
Biopsies should not be taken from the _____ as miniaturized hairs may be present in the region independent of AGA
Bitemporal area
Histologically AGA presents an increased number and proportion of miniaturized (vellus-like) hair follicles with a typically less than _____ ratio of terminal to vellus-like hair follicles compared with a greater than 7:1 ration in the normal scalp
3:1
Histologically AGA presents an increased number and proportion of miniaturized (vellus-like) hair follicles with a typically less than _____ ratio of terminal to vellus-like hair follicles compared with a greater than 7:1 ration in the normal scalp
3:1
Measurement of _____ may be considered depending on patient history, especially when diffuse effluvium is suspected
Ferritin level
Thyroid-stimulating hormone
Acute or chronic diffuse hair loss caused by an increased number of hair follicles in telogen
Reduced hair density over the entire scalp
Associated with a precipitating event, like a severe illness or psychological trauma, crash diet or certain medications
Hair pull test is diffusely positive
Telogen effluvium
Does not follow a patterned distribution
Patchy or total hair loss, hair loss in other body sites, and nail abnormalities
Diffuse alopecia areata
Scarring alopecia of the vertex region that most commonly occurs in women of African descent
Central centrifugal cicatricial alopecia
Frontotemporal band-like scarring alopecia, characterized by frontotemporal band like recession, loss of eyebrows, perifollicular erythema and hyperkeratosis
Lymphocytic scarring alopecia
Frontal fibrosing alopecia
Result of chronic tension on the hair shaft
Hair loss is reversible initially, but may become permanent
History of tight braiding of the hair
Traction alopecia
Diffuse and progressive hair loss of the scalp and the body, beginning during early childhood
Hypotrichosis simplex
