Hair and nails Flashcards
1
Q
Hair types
A
- Lanugo hair: first hair in utero, lightly pigmented and thin
- Vellus hair: fine hairs that covers our bodies
- Terminal hair: coarse, pigmented hair seen in scalp, beard, pubic, axillary regions
- 100,000 hairs on scalp
2
Q
Hair anatomy
A
- From top to bottom
- Infundibulum: from surface to sebaceous gland duct
- Isthmus: from sebaceous gland duct to arrector pilli muscle
- Inferior segment: arrector pilli muscle to bottom of hair (bulb)
- From in to out: medulla, cortex, inner root sheath, outer root sheath
- Stem cells located in the bulge (where arrector pill connects), part of the external root sheath
3
Q
Hair growth cycle
A
- Anagen: growing phase (majority of hairs), lasts about 3 years
- Catagen: destruction phase (very small amount of hairs), lasts 3 weeks. Hairs will retract up to bulge in preparation for new anagen
- Telogen: resting phase (about 20%), lasts 3 months
- Anagen determines the length of a hair
- Bulge cells migrate out during telogen to begin new anagen phase
- In anagen the bulge cells self-renew outside the bulge
4
Q
Alopecia
A
-Loss of hair, can be generalized or localized, can be non-scarring (follicles preserved) or scarring (follicles destroyed, non-reversible)
5
Q
Types of alopecia areatas
A
- Alopecia areata: autoimmune (AI) disease against follicle, increased incidence in AD, downs. Localized loss, patchy
- Alopecia totalis: same mech, but total scalp loss
- Alopecia universalis: same mech, but total body loss
- Can see nail pitting (10%, more organized pitting), exclamation point hairs (diameter decreases closer to follicle)
- use topical steroids to Rx
6
Q
Androgenetic alopecia
A
- Patterned hair loss (most common hair loss in men)
- Polygenic inheritance, dihydrotestosterone (DHT)-dependent transition from large to small caliber hairs
- Age of onset (AOO): 12-40
- On the vertex and/or fronto-temporal regions of scalp
- Rx: topical solutions (minoxidil), hair transplants, finasteride (not for women)
- In women the pattern is diffuse through midscalp (christmas tree pattern)
7
Q
Telogen effluvium
A
- Diffuse shedding of hair (club-shaped hairs)
- Pull test abnormal (more than 6 is abnormal)
- Related to systemic insult to body, pregnancy
- Takes 6-12 months for hair density to return to normal
8
Q
Anagen effluvium
A
- Generalized and diffuse loss of 90% of scalp hair
- Occurs 1-2 mod after trigger (chemotherapeutics)
- Hair shafts thin when on chemo, breaks at surface (no bulb at end of hairs due to fracture)
9
Q
-Trichotillomania
A
- Hair pulling madness, impulse control disorder
- Varying lengths of hairs, do a scalp biopsy
- Increased catagen hairs, melanin within follicular canal
- Rx: behavior modification, SSRIs
10
Q
Traction alopecia
A
- Non-scarring alopecia that can become irreversible
- Due to chronic pulling forces
- Seen in some hairstyles (braids, rollers)
11
Q
Syphilitic alopecia
A
- Inflammatory, non-scarring alopecia
- Manifestation of secondary syphilis
- “moth-eaten” appearance, diffuse hair loss pattern
12
Q
Tinea capitis
A
- Dermatophyte (fungal) infection of the scalp and hair, mostly seen in children
- Patches of alopecia containing broken hairs w/ scale and erythema
- May have inflammatory rxn to dermatophytes, resulting in kerion (boggy pustular plaque)
- Rx is oral antifungal
13
Q
Dissecting cellulitis
A
- Mostly seen in adult black males, scarring alopecia
- Follicular occlusion triad: dissecting cellulitis, hidradentitis suppurativa, and acne conglobata
- Suppurative follicular nodules
14
Q
Acne keloidalis nuchae
A
- Mostly in black males, affects occipital scalp (back of neck), scarring alopecia
- Follicular papules/pustules that progress to firm nodules/plaque
15
Q
Discoid lupus erythematosus
A
- Scarring alopecia can be associated w/ systemic lupus
- PASTE symptoms
16
Q
Kerion
A
- Scarring or non-scarring alopecia
- Dermatophyte infection of scalp and hair follicle
- Large, boggy, erythematous plaque w/ papules, pustules, and crust
17
Q
Hirsutism
A
- Growth of androgen-dependent terminal hair in a women or child in a male pattern
- Can be cause by drugs, tumors, polycystic ovarian disease (POD), congenital adrenal hyperplasia
- POD: most common cause of ovarian hyperandogenism
18
Q
Hypertrichosis
A
- Excessive hair growth on any area of the body
- Can be localized or generalized, can be congenital or acquired
- Acquired hypertichosis languinosa: lanugo hair on face or body, may be paraneoplastic (due to malignancy), drugs, other IC conditions
19
Q
Nail anatomy
A
- Nail plate grows .1mm/day
- Plate comes from nail root (matrix, where nail stem cells are), which is under and behind the cuticle (surrounding skin)
- Thickened layer of skin surrounding the nails is eponychium
- Proximal and lateral nail folds
- Lunula: white crescent shaped area right in front of proximal nail fold
20
Q
Diseases of nails 1
A
- Clubbing of nails due to chronic hypoxia
- Psoriasis often shows oil spots and pitting (irregular) of the nails
- Koilonychia (spoon nails): due to Fe deficiency, anemia
- Terry’s nails: white proximal discoloration from cirrhosis (apparent leukonychia)
- Lindsay’s nails: half-half appearance from renal failure (apparent leukonychia)
- Muehrcke’s lines: paired, transverse white bands, from hypoalbuminemia (malnutrition, cirrhosis, apparent leukonychia)
21
Q
Diseases of nails 2
A
- Blue nails: wilson’s disease (Cu excess), gold rings in iris
- Green nails: from pseudomonas aeruginosa
- Proximal splinter hemorrhages: endocarditis, or trauma
- Onycomycosis/tinea unguium: dermatophyte infection, KOH prep to Dx
- Beau’s lines: transverse depression, result of temporary interruption of mitotic activity of nail matrix. Can be due to trauma, inflammation (eczema, psoriasis)
- True leukonychia (white discoloration, due to distal nail matrix damage): punctate (from trauma), striate (trauma), mew’s lines (striate due to arsenic and thallium poisoning)
