Skin Pathology Flashcards
1
Q
what is a macule
A
primary lesion; small flat (less than 1cm)
2
Q
what is a patch
A
primary lesion; large flat (greater than 1 cm)
3
Q
what is a papule
A
primary lesion; raised (smaller than 1 cm)
4
Q
what is a plaque
A
primary lesion; raised (greater than 1 cm)
5
Q
what is a vesicle
A
primary lesion; small, clear fluid filled (less than 1 cm)
6
Q
what is a tumor/mass
A
primary lesion; raised, deep, and greater than 2 cm
7
Q
what is a pustule
A
primary lesion; white fluid filled
8
Q
what is a bulla
A
primary lesion; large, clear fluid filled (greater than 1 cm)
9
Q
mechanism of papule or plaque formation
A
proliferation of cells in epidermis or superficial dermis
10
Q
what is a nodule
A
primary lesion; usually greater than 1 cm, deep and palpable
11
Q
mechanism of nodule formation
A
proliferation of cells into the mid-deep dermis or fat
12
Q
erythematous means
A
red FROM inflammation
13
Q
additional descriptors for primary lesions
A
- color
- size
- texture
14
Q
what is scale
A
secondary change; accumulated skin (stratum corneum)
15
Q
what is crust
A
secondary change; died exudate: blood, serum, pus
scab
16
Q
what is excoriation
A
secondary change; traumatized due to scratching
17
Q
what is erosion
A
secondary change; depression with loss of epidermis (superficial)
18
Q
what is ulceration
A
secondary change; depression with loss of epidermis and dermis (deeper than erosion)
19
Q
what is fissure
A
secondary change; linear cleavage
20
Q
what is lichenification
A
secondary change; thickening, accentuated skin line
21
Q
what is atrophy
A
secondary change; depression, thinning, wrinkling
22
Q
what is scar
A
secondary change; permanent fibrotic change
23
Q
if something is vascular/vasculitic it will not
A
blanch with pressure
24
Q
petechiae/petechial is a secondary descriptor. what does it mean
A
acute to subacute leakage of capillaries within skin; generally pinpoint to small
25
purpura/purpuric is a secondary descriptor. what does it mean
acute to subacute leakage of capillaries or small-larger vessels within skin; usually larger; may be palpable
26
ecchymotic is a secondary descriptor. what does it mean
subacute to chronic hemorrhage within skin; usually larger
27
examples of configuration
```
•solitary
•discrete
•annular
•confluent/coalescent
•clustered/grouped
•linear
reticular (net-like)
```
28
what does the term acral mean in the context of distribution pattern
the most distal part (hands, feet, tip of nose)
29
how to describe skin findings
distribution, configuration, color/size primary lesion with +/- secondary change
30
causes of impetigo
* staph aureus (more common)
| * strep pyogenes
31
common location of impetigo
around mouth or perineum
32
description of impetigo
crusted, "glazed" eroded papule to plaque, peripheral rim of scale
uncommonly bullous -> blisters
33
impetigo can be tender or asymptomatic. how is it treated
topical or oral abx
34
impetigo is rarely biopsies, but what would be seen histologically
subcorneal neutrophils and scattered gram + cocci
| usually doesn't invade beyond epidermis
35
description of cellulitis
* edematous, erythematous, warm, sometimes taut/shiny localized plaque
* usually solitary
* uncommonly blisters surface due to edema
36
cellulitis may be present with or without fever and other systemic sxs. what is the treatment
* systemic abx (PO or IV)
| * rest elevation
37
necrotizing fasciitis is usually deeper tissue injury than cellulitis. what usually causes it
anaerobic bacteria or group A strep pyogenes
38
description of necrotizing fasciitis
purple, dusky necrotic color +/- ulcers and bullae
39
necrotizing fasciitis is a surgical emergency and is associated with
severe, intense pain and systemic symptoms
40
In staph scalded skin syndrome, staph aureus produces
epidermolytic-toxin that causes cleavage/split within epidermis
41
what demographic is typically affected by SSSS, and why?
* infants and younger kids b/c they have physiologically decreased renal function
* also those who are immunocompromised
42
those affected by SSSS are usually febrile and have peeling that is accentuated at perioral areas and body folds. where is the most common primary infection?
nasopharynx
43
why is the area of primary infection important in staph scaled skin?
that is the area that must be cultured
44
SSSS doesn't have any true mucosal involvement. what is the treatment?
systemic anti-staphylococcal abx (PO or IV)
45
histologically how could a biopsy of SSSS be differentiated from impetigo?
there are no organisms in the subcorneal blister of SSSS because it is a toxin-mediated effect
46
what are they cytopathic effect of herpes virus on keratinocytes?
the 3 Ms
•margination of chromatin
•multinucleation
•molding of nuclei (clumping together)
47
HSV1 more commonly affects
oral
48
HSV2 more commonly affects
genital
49
initial infection of HSV can range from
asymptomatic to fulminant stomatitis (rare)
50
Description of shingles (VZV) rash
* dermatomal distribution disseminated papules, vesicles, plaques, bulla
* itchy, painful
* +/- systemic symptoms
51
concerning presentations of VZV
* ophthalmic involvement -> possible blindness
| * Ramsay-hunt syndrome -> facial palsy, ear pain
52
Histopathology of VZV
identical to HSV! 3Ms
| Need PCR to discriminate between the 2
53
what are verruca and what the cause
warts; HPV
54
vulgaris verruca
common wart
55
condyloma acuminata
genital warts
56
histology of verruca vulgaris
* papillomatous epidermal acanthosis
* hyperkeratosis
* hypergranulosis
57
what is molluscum contagiousum
in the pox virus category
58
description of molluscum contagiosum
```
•dome-shaped papules with waxy surface
•single or multiple
•may be pruritic
•~5mm
"papule with central umbilication"
```
59
what is seen histologically in molluscum contagiosum
henderson-patterson bodies = accumulation of virus into brick-like structures
60
location of molluscum contagiosum lesions
trunk, face, axillae, genital area (STI)
61
how does molluscum contagiosum spread
with scratching
62
what are tinea
40+ species of fungi that "feed" on dead skin (dermatophyte infection)
63
species that cause tinea fall in which genera
* tricophyton
* microsporum
* epidermophyton
64
what stain can be used for tinea
KOH stain the stratum corneum
| *fungal culture if inconclusive
65
fungal forms of tinea can be difficult to see on HandE stain, but what might be identifiable?
altered cornified layer with intracorneal neutrophils
66
tinea pedis
athlete's foot
67
tinea corporis
ringworm occurs anywhere on the body
68
tinea manuum
hand (usually left)
69
tinea cruris
jock itch
70
tinea capitis
scalp
71
tinea onychomycosis
nails
72
tinea versicolor (pityrosporum)
not technically tinea, b/c caused by yeas organism, but lumped in because similar presentation
73
bacterium that causes syphilis
treponema pallidum (spiral shaped bacteria)
74
primary syphilis infection (treponema pallidum)
solitary or multiple painless genital "chancres"
75
secondary syphilis infection (treponema pallidum)
rash and condyloma lata, systemic symptoms, moth-eaten alopecia
76
tertiary syphilis infection (treponema pallidum)
gummas (granumolas), aortitis, neurosyphilis, etc
77
congenital syphilis (treponema pallidum)
stillbirth, acral bullae/erosions, rhinitis, rhagades, deafness
*highly infectious
78
what is sarcoptes scabiei
the human itch mite
| an arthropod that burrows under the skin and causes scabies
79
scabies infection occurs when
adult female sarcoptes scabiei burrows into the epidermis and lays eggs
80
transmission of scabies
close skin contact
81
description of scabies
* usually exceedingly pruritic
| * moth-eaten papules, burrows
82
what histologic prep may be useful in diagnosing scabies?
mineral oil prep
83
where does scabies infection occur
* hands, feet, waistline/genitals
| * infants may have atypical presentation
84
cutaneous infections caused by arthropod
scabies
85
cutaneous infections caused by bacteria
impetigo, cellulitis, SSSS
| syphilis (treponema=spiral bacteria)
86
cutaneous infections caused by dermatohyte (fungus)
tinea
87
cutaneous infections caused by virus
HSV, VSV, molluscum contagiosum
88
subcutis is underneath the dermis and is also called
panniculus
89
stratum corneum
* composed of dead, anucleated keratinocytes
| * protects against environment and external pathogens
90
stratum lucidum is only normally found
•on thickened skin (palms and soles)
91
stratum granulosum (aka granular layer) have keratinocytes with heratohyalin granules that
are exocytosed to produce a water-proof barrier
92
stratum spinosum (aka spiny layer)
* provided structural support
| * home of langerhans cells
93
cellular junctions in stratum spinosum
desmosomes (have pairs), look like spines
94
stratum basale (basal layer)
* connects epidermis to dermis
| * home of melanocytes and stem cells
95
cellular junctions in stratum basale
hemidesmosome (no pairs)
96
merkle cells are somewhat of a mystery but serve the purpose of
group together to form a receptor for touch (sustained pressure/deep static touch)
97
melanocytes are derived from
neural crest
98
langerhans cells are located in stratum spinosum and act as
* antigen presenting cells (APCs)
| * mediators of immune response
99
langerhans cells contain
birbeck granules, which look like tennis rackets
100
what is found only in the dermis, and not the epidermis
blood vessels, lymphatics, and nerves
101
fibroblasts are the main cells of the dermis and produce
collagen, elastin, and ground substance
102
free nerve endings in the dermis have 2 kinds
* c-type: small, slow, unmyelinated
| * A delta type: small, fast, myelinated
103
meissner corpuscles sense what in dermis
light touch, vibration, and position
104
pacinian corpuscles sense what in dermis
vibration and pressure
105
ruffini corpuscles sense what in dermis
stretching, continuous pressure, proprioception
106
merkle disks sense what in dermis
sustained pressure
107
what kind of secretion occurs in sebaceous glands
holocrine
108
where do sebaceous glands empty
into hair follicles; not directly onto skin
109
where are sebaceous glands located
everywhere except palms and soles
110
which sweat glands cause body odor
apocrine sweat glands
111
where are apocrine sweat glands located?
axilla, areola, ear canal, eyelids, and anogenital area
112
where are eccrine (merocrine) sweat glands located
everywhere except mucous membranes
113
histologic comparison of apocrine and eccrine (merocrine) sweat glands
* apocrine: more pink, larger ducts
| * eccrine: more purple, more compact ducts
114
where do apocrine and eccrine (merocrine) sweat glands empty
directly onto skin surface
115
which sweat glands are important for thermoregulation?
eccrine (merocrine) sweat glands
116
secretion of eccrine sweat glands regulated by
sympathetic nervous system
117
secretion of sebaceous glands regulated by
primarily hormonal control
118
orthokeratosis or hyperkeratosis is
thickened stratum corneum
119
orthokeratosis/hyperkeratosis occurs where
palms/soles (naturally)
| chronically rubbed/irritated skin
120
parakeratosis is
dead cells within the stratum corneum that retain their nuclei
121
clinical example of parakeratosis
psoriasis
122
acanthosis is a protective mechanism. what occurs
thickened/elongated spinous layer
123
clinical examples of acanthosis
* psoriasis
| * lichen planus
124
acantholysis is
lysis of cells in the spinous layer
125
clinical example of acantholysis
pemphigus
126
psoriasis presents with
* parakeratosis
* acanthosis
* neutrophils in stratum corneum
127
what is a histiocyte
a macrophage in the skin
128
eosinophils looks like "raspberries wearing sunglasses." when they are in the skin, think
allergy!
129
mast cells look like fried eggs. in the skin the can ___ and cause ___
degranulate -> itch
130
plamsa cell histologic appearance
large, purple, peripheral nucleus
131
acrochordon is
skin tag
132
acanthosis nigricans presentation
* hyperpignemted velvety plaque, looks dirty
* +/- acrochordons
* posterior neck fold, axillae most common
133
what does acanthosis nigricans indicate
insulin resistance
134
what is malignant acanthosis nigricans
* in unusual locations and/or sudden onset
* "tripe palms"
* most common: gastric adenocarcinoma
* less common: other adenocarcinoma
135
what is the sign of leser-trelat
* sudden onset numerous seborrheic keratosis
* may be associated with malignant acanthosis nigricans
* underlying malignancy usually aggressive
136
what is dermatitis herpetiformis commonly associated with
celiac disease
137
what is dermatitis herpetiformis
•autoimmune blistering disease
138
what does dermatitis herpetiformis look like
extremely itchy papules/vesicles, particularly on extensor (sometimes only see erosion b/c scratching)
139
what is required to diagnose dermatitis herpetiformis
biopsy and direct immunofluorescence (DIF) because it may resemble eczema
140
what is the autoimmune reaction in dermatitis herpetiformis
IgA autoantibodies to:
•tissue transglutaminase
•epidermal transglutaminase
•gliadin
141
HLA association with dermatitis herpetiformis
HLA DQ2 and HLA DQ8
142
what is vitiligo
autoimmune attack on melanocytes
143
what does vitiligo look like
* depigmented macules and patches
| * favors areas of trauma
144
what can be helpful in diagnosing vitiligo
woods lamp (black light)
145
difference between albinism and vitiligo
vitiligo -> melanocyte get attacked/killed
| albinism -> melanocytes present, just don't work
146
what is a butterfly rash and what's it associated with
* red on the face and sparing nose and nasolabial folds
| * systemic lupus erythematosus
147
what is systemic lupus erythematosus (SLE)
* chronic autoimmune inflammatory disease
| * butterfly rash associated
148
what will you see histologically in (SLE)
* mucin = red scaly plaques
* inflammatory cells eating keratinocytes -> premature death
* red=dead
149
what does subacute cutaneous lupus erythematosus (SCLE) look like
* scaly erythematous plaques; annular/polycyclic, psoriasiform
* favor photodistribution
* highly sensitive to sun exposure
150
what does discoid lupus erythemtosus look like
* erythematous to violaceous scaly plaques
* follicular plugging
* hypo/hyperpigmentation
* +/- scarring and atrophy
151
dermatomyositis is considered a paraneoplastic process. what skin findings are there
* heliotrope rash (eyelids)
* gottrons papules (hands/elbows)
* erythematous to dusky lilac patch-plaques, usually with minimal scale
152
what is dermatomyositis
autoimmune inflammatory myopathy with characteristic skin findings
153
most common malignancies found in those with dermatomyositis
* ovarian
* breast
* melanoma
* colon
* non-hodgkins lymphoma
154
what is erythema nodosum
* hypersensitivity reaction usually limited to shins
| * inflammation in the fat (panniculitis)
155
findings in erythema nodosum
* acute tender nodular eruptions
| * giant cells in panniculus
156
associations in erythema nodosum
* infections
* medications
* pregnancy
* systemic disease
157
what is pyoderma gangernosum
uncommon neutrophilic disease
158
presentation in pyoderma gangrenosum
scarring, painful deep ulers with "gun mettal" rolled or raggidy borders (necrotic)
159
most common underlying association with pyoderma gangrenosum is
inflammatory bowel disease
160
what is pathergy
new ulcers at the sites of skin trauma in pyoderma gangrenosum
*DONT debride
161
what is cutaneous T-cell lymphona (aka mycosis fungoides)
lymphoproliferative disorder
162
what is seen in cutaneous T-cell lymphoma
* chronic, non-responsive erythamtous scaly plaques
| * trunk and sun protected areas most common
163
what is seborrheic keratosis
benign proliferation of keratinocytes that is common in older people. NO atypia or mitoses
164
what is a prominent horn cyst
a keratin pearl that may be seen histologically in seborrheic keratosis
165
characteristics of benign lesions in skin
symmetric, distinct border, homogenous color, smaller, stable/unchanging
166
melanocytic nevi are described by which portions of the skin are involved. what are the subtypes
* junctional - only in epidermis, flat
* compounds - epidermis and dermis
* intradermal - only dermis, raised
167
ABCDEs of detecting melanoma
asymmetry, border, color, diameter, evolving
168
what is the most common kind of melanoma
superficial spreading
169
what subtype makes up majority of melanomas arising in dark skinned races
acral letiginous
170
lentigo maligna is a melanoma usually seen on
usually face of older person with hx of lots of sun exposure
171
what is pagetoid spread
upward intraepidermal spread of melanocytes
| *sign of malignancy
172
what histopathologic feature of melanoma is most important for prognosis
depth of invasion
173
what is the most important/common mutation found in melanoma
BRAF V600E
174
what is the most common type of skin cancer
basal cell carcinoma
175
basal cell carcinomas occur in areas of sun exposed skin. what is the clinical presentation
* pearly or shiny
* papules with subastance
* erosion/ulceration
* bleed easily with minimal trauma
* can be pigmented (look gray, blue, or black)
* telangectasias (torturous blood vessels)
176
histopathology of basal cell carcinoma
nests of basaloid cells with stromal clefting, palisading nuclei, and mucin
177
basal cell carcinoma is the most common skin cancer. Classify its aggressivity
•locally aggressive, rarely metastasizes
178
Actinic Keratosis is a premaligant condition that can present with
extensive, rough erythematous papules
179
histopathology of actinic keratosis
SPA
•Solar elastosis (accumulation of elastin in dermis)
•parakeratosis (nucleated s. corneum)
•atypia of basal keratinocytes
180
if untreated, 10% of actinic keratosis will progress to
squamous cell carcinoma
181
histopathology of squamous cell carcinoma in situ (SCCIS)
* atypical keratinocytes - full thickness of epidermis
| * mitoses throughout epidermis
182
presentation of SCCIS (bowens disease)
* relatively well defined, localized
* slightly scaly
* thin (not indurated)
* pink plaque
* NO erosion, ulceration, or marked thickening
183
histopathology of invasive squamous cell carcinoma
* atypical keratinicytic proliferation
* invades into dermis/subcutis
* prominent keratin pearls
184
what is the second most common skin cancer
squamous cell carcinoma
185
which is more likely to metastasize squamous cell or basal cell carcinoma
squamous cell carcinoma
186
pathogenesis of squamous cell carcinoma
* most commonly exposure to UV light
| * increased risk in immunosuppressed
187
which UV is more prominent in sunburn
UVB - sunBurn
188
which UV is more prominent in tanning and photoaging
UVA - tAnning and photoAging
189
what is xeroderma pigmentosum
* rare, autosomeal Recessive
* deficient nucleotide excision repair pathway
* risk for early onset skin cancer
190
what mutation is associated with nevoid basal cell carcinoma syndrome (Gorlins)
PTCH mutation
191
mutation associated with dysplastic nevus syndrome
CDKN2A genes
192
what is dysplastic nevus syndromes
cutaneous condition with unusualy nevi and multiple inherited melanomas
193
what is a pyogenic granuloma (aka lobular capillary hemangioma)
common benign vascular tumor
194
what occurs in pygenic granuloma (aka lobular capillary hemangioma)
* overgrowth of granulation tissue
| * often following minor trauma or foreign body•
195
location of pyogenic granuloma (aka lobular capillary hemangioma)
face or extremity (usually hands)
196
description of pyogenic granuloma (aka lobular capillary hemangioma)
* solitary, bright red, soft nodule
* pedunculated (has stalk/stem)
* 5-6 mm
* friable surface
197
location of infantile hemangioma (most common vascular tumor of infancy)
* >50% head/neck
* 25% trunk
* extremities
198
timing of infantile hemangioma
several days to weeks after delivery
199
what is a cherry angioma
benign vascular neoplasm in adults
200
presentation of cherry angioma
* multiple, small, dome-shaped discrete deep red papules
* can bleed secondary to trauma
* mocosa spared
201
location of cherry angioma
trunk and upper arms
202
glomus bodies are involved in thermoregulation, and are numerous in the fingers and toes. What is a glomus tumor
* rare benign neoplasm from glomus body
| * usually under nails, painful
203
what is kaposi sarcoma
* malignant vascular tumor
| * usually seen in immunosuppressed or transplant patients
204
what can be stained for in diagnosis of kaposi sarcoma
HHV-8 (human herpes virus)
205
what is angiosarcoma
* rare malignant neoplasm of sun damaged skin
| * classic: older caucasian male scalp
206
biopsy of seborrheic keratosis would show
* horn cysts
* string sign
* no atypia
207
What is bullous pemphigoid
autoimmune disorder with autoantibodies against hemidesmosomes
*remember Bullous=Below epidermis=hemidesmosome problem
208
direct immunofluorescence for bullous pemphigoid shows
linear subepidermal deposition of IgG
209
direct immunofluorescence for pmnphigus vularis would show
net like IgG fluorescence patterns
210
what is the autoimmune reaction in pemphigus vulgaris
autoantibodies to components of desmosomes, namely desmogleins 1 and 3
-> intraepidermal blisters
211
characterize the skin lesions in bullous pemphigoid
tense bullae and vesicles on normal to erythematous skin
212
contrast presence or absence of oral/mucosal involvement in bullous pemphigoid and pemphigus vulgaris
* no oral involvment in bullous pemphigus (or rare)
| * pemphigus vulgaris does have oral involvement
213
characterize skin lesions in pemphigus vulgaris
flacid bullae with erosions
214
what is nikolsky's sign
skin reddens, fluid collects underneath and skin rubs off leaving raw base
*happens in pemphigoid vulgaris
215
when would you see tombstoning in histology
in pemphigus vulgaris
216
age of patients with bullous pemphigus
older patients, usually 70 or older
217
prognosis in pemphigus vulgaris
most patients die without treatment
218
what is tombstoning
the tombstone appearance of the basal layer
| *seen in pemphigus vulgaris
219
what would you see histologically in bullous pemphigoid
eosinophilic infiltration and subepidermal blister (deep)
220
what are urticarial eruptions
* hives
* Wheals with white-to-light-pink color centrally and peripheral erythema
* worse with repeat exposure
221
timing of urticaria
* transient
* 1 hive will last no longer than 48 hours
* variable time of onset
222
causes of urticaria
* any drug exposure
* viral infections
* idiopathic
223
what is a morbilliform eruption
"measles-like"
| only true maculopapular rash
224
timing of morbilliform eruption
usually starts 7-10 days after exposure
225
causes of morbilliform eruption
common: penicillins, cephalosporings, other abx
| can be viral infection, esp in kids
226
what is erythema multiforme ("majore")
* self limited hypersensitivity syndrome
* ~90% cause d by HSV1
* "Major" if mucous membrane involvement
227
what does the rash look like with erythema multiforme
targetoid eruptions that may or may not be bullous or crusty
228
distinction of urticarial rash vs erythema multiforme
* urticaria, central zone is normal skin
| * erythema multiforme, central zone is damaged skin
229
Stevens-johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is a hypersensitivity disorder. which one predominated in children
stevens-johnson
230
what are the most common medications associated with SJS/TEN?
* anti-epileptics
* sulfonamics
* PCNs
* Allopurinol
* NSAIDs
231
illnesses that can be associated with SJS/TEN
viruses
| mycoplasma
232
presentation of SJS/TEN
* fever/malaise
* mucosal pain/ swelling
* photophobia
* erythematous macular eruptions that can quickly evolve to vesicles/bullae
233
what is seen histologically with SJS/TEN?
complete separation of epidermis from dermis
| RED=DEAD
234
what might cause earlier or later onset acne
androgen dysfunction or polycystic ovarian syndrome (PCOS)
235
what is the acne pathogenesis
1. pilosebaceous unit obstruction
2. increased sebum production (hormonal influence at puberty)
3. bacterial proliferation (prpionibacterium acnes)
4. +/- inflammation
236
what can trigger new acne in a post-pubertal person
* anabolic steroids
* corticosteroids
* mood-stabilizing meds
* protein supplementation
237
stages of acne
* open comedo -> black head
* closed comedo -> whitehead
* papule
* pustule
238
what are the more severe presentations of acne
* acne conglobata
* acne fulminans
* multiple connecting sinuses/tracts
* can have systemic symptoms
239
what is acne excoriee
"factitial dermatitis"
•exogenous manipulation
•often in setting of anxiety, OCD or body dysmorphic issues
240
what is postinflammatory dyspigmentation
* increased melanin deposition within epidermis after inflammation
* more common with darker skin types
241
what is hidradenitis suppuitiva
chronic acneiform inflammatory condition that affects body folds with painful, draining sinuses
242
folliculitis can be caused by exposure to what
hot tub -> pseudomonas
243
what does folliculitis look like
* follicularly centered papules or putules
| * can be itchy/painful
244
where do you find vellus hairs
fine hairs like on cheeks and forehead
245
where do you find terminal hairs
axillary, pubic, scalp, bear, eyebrow
246
what is glaborous skin
areas without hairs: palms + volar surface of fingers and soles
247
which areas of follicles are more dependent on hormone singnalling?
* frontal and vertex scalp (top of head)
| * lateral face and jawline
248
which areas of follicles are more independent of hormone signalling
* occipital scalp
| * central face and forehead
249
on average, how many hairs do we normally shed per day
about 100
250
what is the anagen phase of the hair follicle cycle (terminal scalp hair)
* Anagen=Active; hair shaft growing
| * 85-90% of scalp hairs in anagen phase at any time
251
what is the catagen phase of hair follicle cycle (terminal scalp hair)
* regression of the follicle (2-3 weeks)
| * less than 1% of scalp follicles at any time
252
what is the telogen phase of hair follicle cycle (terminal scalp hair)
* resting phase, can be up to 3 months
| * 10-15% of scalp follicles at any time
253
what is the exogen phase of hair follicle cycle (terminal scalp hair)
* shedding of hair shaft; early part of anagen phase as follicle starts to regenerate and grow new hair shaft
* mechanical displacement of old hair shaft and protelytic process freeing shaft from follicle
254
what is alopecia areata
localized (scalp) autoimmune phenomenon, can be associated with other autoimmune conditions (thyroid)
255
what does alopecia areata look like
geometric, clean patterning, non scarring
256
male pattern androgenetic apopecia can be associated with
•higher 5-alpha reducatase level, lower total testosterone, or higher free androgens
257
what is trichotillomania
•hair pulling behavioral disorder on obsessive-compulsive spectrum. may have associated anxiety/depression
258
what is Anagen effluvium
* insult to hair follicle, impairing mitotic activity (ie chemo)
* diffuse shedding of ACTIVELY GROWING hairs
259
what is telogen effluvium
* occurs with abrupt shift so all telogens are in phase
| * diffuse shedding all at once of RESTING hairs
260
what things might cause telogen effluvium
post-partum
stress
illness
