Apr12 M2-Hair and Nails Flashcards
nail anatomy
proximal nail fold = base
lateral nail fold = skin on both sides
nail plate = nail part near lateral fold
onychodermal band = nail part near finger tip
lunula = whiter part near base
cuticle = tissue on base
matrix = most important part under the lunula. produces the nail
most important part of the nail and location
nail matrix. white tissue (see that it’s white if remove nail) under the lunula.
nail bed def
bed on which the nail rests, extending from lunula to hyponychium (which is the skin under the nail on the finger tip)
3 year old with sudden onset of shedding of nails and separation of nail plate from bed: different possible causes
- trauma (manicure, onychotillomania)
- eczema, erythroderma
- severe systemic conditions
- high fever
- viral illness
3 year old with sudden onset of shedding of nails and separation of nail plate from bed: name of the condition and important related cause
onychomadesis
-hand foot and mouth disease caused by enteroviruses
tx of onychomadesis
nail will grow back
nail pitting (holes in the nail) means what
can be associated with
- psoriasis
- eczema
- alopecia areata
- trauma
swelling and redness around nail + painful erythmatous and purulent swelling of nail folds dx
acute paronychia
cause of acute paronychia
staph aureus
chronic paronychia looks like what
- rednes and swelling around thumb, inflammed folds, dystrophic plate, not purulent
- candida and irritation caused by saliva
group of pustules (pustular vesicular lesions) on fingernail and finger tip: name of that
herpetic whitlow
- HSV1 or 2 infection of fingertip and perionychium
- pain edema and erythema (and the pustular grouped vesicles**)
(imp?) brown line on the nail is what
melanonychia
- think of melanoma refer to dermatology
- nail matrix nevus or lentigo
- subungal melanoma
racial melanonychia is what
- melanonychia involving several nails
- benign
thick yellow toenails + debris under the nails: name of this SYMPTOM
subungal hyperkeratosis
nail plate separated from nail bed
disease where you see subungal hyperkeratosis and cause
onychomycosis
caused by fungal infections
most common type of onychomycosis
distal subungual onychomycosis
(imp?) distal subungual onychomycosis charact
- onycholysis (bed-plate separation)
- subungual hyperkeratosis
- invasion of inferior plate
- yellow brown discoloration
white superficial onychomychosis charact
- superficial infection of nail plate
- well demarcated opaque friable plaque on dorsal plate (outer)
dx of onychomycosis
- KOH coloration and smear
- fungal culture
- PAS stain (periodic acid Schiff)
tx of onychomycosis
oral antifungal for 4 months
diff parts of the hair
- hair shaft = above scalp
- hair root= in scalp
- hair follicle = hole of the root
- hair bulb = matrix cells making bottom of hair root
- sebaceous glands to make sebum and keep hair and skin waterproof
3 phases of hair growth
- anagen
- catagen
- telogen
anagen phase charact
- lasts 1000 days
- matrix cells geown and become keratinized
catagen phase charact
matrix cells suddenly stop proliferating
telogen phase charact
100 days
-hair shedding phase, goes out of the follicle
alopecia def and 2 things to check
means hair loss
- localized vs diffuse
- cicatricial or non cicatricial (scarring)
cicatricial vs non cicatricial hair loss
cicatricial = lack of follicular ostia (holes) + shiny atrophic skin
non cicatricial = see hair follicles
(important) alopecia areata def
autoimmune disease of patchy, non itchy, non scarring, non edematous hair loss
tinea capitis def
circular patches of hair loss, itchy and scaly. broken hair
cause of tinea capitis
dermatophyte fungi
tinea capitis kerion def
- inflammatory mass surrounded by follicular pustules
- fever and local lymphadenopathy
- severe and reactive infection. form of tinea capitis
cause of tenia capitis kerion
fungal infection
specific fungus that often causes tinea capitis
T. tonsurans
dx of tinea capitis
- scraping
- KOH
- culture
(IMPORTANT) tx of tinea capitis
ORAL anti fungal
topical therapy is just to reduce infectivity
trichotillomania def
- habitual compulsive plucking of hair
- broken hairs
- frontotemporal or parietotemporal regions
3 important things in trichotillomania
- have access to this area of hair
- pattern of hair loss
- hair of different length
tx of trichotillomania
- stop habbit
- psychiatric evaluation
androgenetic alopecia charact
androgenetic alopecia in men vs women
men = vertex (top of scalp) then bitemporal then both join women = diffuse central thinning of the crown with preservation of the frontal hair line
androgenetic alopecia cause
- testosterone is transformed to DHT by 5 alpha reductase (enzyme in hair follicles)
- have more levels of 5a reductase = have more androgen receptors
- DHT leads to thinning and miniaturization of hair
AGA (androgenetic alopecia) how androgen levels are diff from other people
NORMAL ANDROGEN LEVELS
just more 5a reductase and more androgen Rs
DHT exact effect
-shortens growth phase from 3-6 years to a few weeks or months
telogen effluvium charact
-premature shift of hair follicle to the telogen phase caused by some triggers (surgery, bad disease, fever, etc.)
(imp?) triggers of telogen effluvium
SEND
Stress (psychosocial, surgery, systemic disease)
Endocrine (hypo, hyperthyroidism)
Nutritional (iron deficiency, etc.)
Drug (acitretin, anticoagulant, allopurinol)
telogen effluvium evolution
- shedding for 3-4 months after initiating cause
- 6-12 months for hair density to go back to normal
