16 - 85 - ANDROGENETIC ALOPECIA Flashcards
nonscarring progressive miniaturization of the hair follicle in genetically predisposed men and women, usually in a specific pattern distribution
Androgenetic alopecia (AGA)
what stage of the hair cycle shortens in AGA?
anagen
This is the most frequent clinical pattern in men with AGA, and only occasionally observed in women
MALE PATTERN, HAMILTON- NORWOOD TYPE
Recession of the frontal hairline, mainly in a triangular pattern is the characteristic finding, later followed by a vertex thinning with progression until the top of the scalp is completely bald
MALE PATTERN, HAMILTON- NORWOOD TYPE
what areas of the scalp are spared even in longstanding male pattern hair loss?
Occipital area and sides of the scalp
characterize the female pattern hair loss
diffuse thinning of the** centroparietal region with maintenance of the frontal hair line**
describe male pattern hair loss
- Recession of the frontal hairline, mainly in a triangular pattern is the characteristic finding, later followed by a vertex thinning with progression until the top of the scalp is completely bald
- Occipital area and sides of the scalp are spared even in longstanding male pattern hair loss
scales used to describe female pattern hair loss
- 3-point Ludwig scale
- 5-point Sinclair scale
most common type of AGA in women
FEMALE PATTERN, LUDWIG TYPE
- diffuse thinning of the centroparietal region with maintenance of the frontal hair line
shows diffuse centroparietal thinning similar to the Ludwig pattern with an additional breaching of the frontal hair line
Christmas tree pattern
characterize the Christmas tree pattern observed frequently in women
diffuse centroparietal thinning similar to the Ludwig pattern with an additional breaching of the frontal hair line
- in Ludwig, frontal hairline is maintained
androgen chiefly responsible for the follicular pathology in AGA
Dihydrotestosterone
- Dihydrotestosterone probably acts primarily on **dermal papilla, **the predominant site of androgen receptor and type II 5α-reductase expression within the hair follicle
what enzymes are elevated in balding scalp skin?
prostaglandin D2 synthase and its product prostaglandin D2
prostaglandin D 2has an inhibitory effect on hair growth in animal and in in vitro experiments
how do you do a hair pull test (Sabouraud maneuver)
- approximately** 50 to 60 hairs** are grasped between the thumb, index, and middle fingers from the base of the hairs near the scalp and firmly, but not forcefully, tugged away from the scalp.
* If more than 10% of the grasped hairs are pulled away from the scalp, this constitutes a positive pull test and confirms active hair shedding
In AGA, the hair pull test may be positive and negative in what areas?
In AGA, the hair pull test may be positive in the frontal region, while it is typically negative in the occipital region.
The preferred area for biopsy in AGA
central scalp in an area representative of the hair loss process
- Biopsies should not be taken from the bitemporal area as miniaturized hairs may be present in this region independent of AGA
histopath findings of AGA
- increased number and proportion of miniaturized (vellus-like) hair follicles with a typically less than 3:1 ratio of terminal to vellus-like hair follicles, compared with a greater than 7:1 ratio in the normal scalp
* increased telogen-to-anagen ratio - an increase in the number of follicular stelae (tracts beneath miniaturized follicles).
- A mild perifollicular lymphohistiocytic infiltration, primarily around the upper hair follicle, also may be present, as well as perifollicular fibrosis, in longstanding AGA
DDx
■ Associated with precipitating event
■ Hair pull test diffusely positive
Telogen Effluvium
DDx
■ No pattern of distribution
■ Personal or family history of alopecia areata
■ Hair loss in other body sites
■ Nail changes
Diffuse Alopecia Areata
DDx
■ Scarring alopecia of the vertex region
■ Most commonly in women of African descent
■ Dermoscopy and histologic evaluation shows scarring alopecia
Central Centrifugal Cicatricial Alopecia
■ Frontotemporal, band-like scarring
■ Associated with loss of eyebrows
■ Perifollicular erythema and hyperkeratosis
■ Histology shows lymphocytic scarring alopecia
Frontal Fibrosing Alopecia
DDx
History of chronic tension in the hair shaft (tight braiding)
Traction Alopecia
■ Diffuse, progressive loss of scalp and body hair from early childhood
■ No anomalies of skin, nails, or teeth
Hypotrichosis Simplex
DDx
■ Skin, appendages, nails, and teeth associated
■ Delayed physical/psychological development and sweating disorders
Ectodermal Dysplasia
course and prognosis of AGA
- naturally progressive, meaning that the main therapeutic aim is the improvement or even merely prevention of disease progression
- Irrespective of its clinical progression, AGA provokes significant distress and has an often underestimated psychosocial impact on the affected patients.
How is minoxidil applied?
Male > 18 years old
* mild to moderate AGA: 2% to 5% solution; 1 mL or half a cap of 5% foam twice daily
Female > 18 years old
* mild to moderate AGA: 2% solution; 1 mL twice daily or half a cap of 5% foam once daily
To avoid contamination of the pillow with subsequent facial contact patients should be advised to apply the drug at least 2 hours before going to bed
The response to treatment should be assessed at how many months?
6 months
If successful, treatment needs to be continued to maintain efficacy
The patients should be informed about transitory increased telogen hair shedding, usually appearing within how many weeks of using minoxidil?
first 8 weeks of therapy initiation
Furthermore, after end of therapy with topical minoxidil, increased hair loss follows.
main side effect of topical minoxidil
hypertrichosis, mostly from local spreading or excessive continuous topical application
In male patients older than 18 years of age with mild to moderate AGA, what systemic therapy can be given?
5α-reductase type 2 inhibitor finasteride (1 mg/day)
- For greater efficacy, the combination of oral finasteride (1 mg once daily) and topical minoxidil can be considered.
- Patients under treatment with finasteride should be aware of reduction of prostate-specific antigen, which is important in prostate cancer screening in men.
reported side effects of finasteride
impaired sexual function, including erectile dysfunction, ejaculation dysfunction, reduced ejaculate volume, and loss of libido
treatment options for AGA
