PATHOPHYS Flashcards
what is the major UVB chromophore in the skin?
DNA
what are the 3 main things that can happen when sunlight hits the skin?
- some reflected
- some absorbed in epidermis & dermis by DNA, proteins and other substances
- some penetrates deeper into tissues and is dissipated
which spectrum of light causes an immediate tanning response?
UVA and visible light
which spectrum of light causes a delayed tanning response?
UVB
what are solar lentigenes?
age spots (from photodamage)
How can sundamage cause immunosuppression?
- lymphocytes and Langerhans cells are sensitive to UV induced DNA damage
- langerhans cells disappear from skin following sun exposure strong enough to cause a mild sunburn
what are the 2 most common causes of death in xeroderma pigmentosum?
metastatic skin cancer and neurologic degeneration
which diseases are treated with UV light?
psoriasis
cutaneous lymphoma
eczema
tanning beds mostly emit which type of UV light?
UVA
which type of tan provides more protection against a sunburn UVA or UVB?
UVA induced tans provide 10 times less protection than UVB tans
the risk of skin cancer increases by ____________% in individuals who start using tanning beds before 30.
75%
what is the mechanism behind a delayed tanning response?
increased melanin synthesis and increased transfer of melanosomes to keratinocytes
Name the 2 common DNA photoproducts from UV damage
cyclobutane dimers
6,4 photoproducts
what are the 2 signature mutations induced by UV light?
C–>T
CC–>TT
which skin cancer has a corrlation with mutation in PTCH gene?
basal cell carcinoma
Name the pathology:
pearly, nodular, shiny, centrally ulcerated and studded w/ telangiectasias on gross appearance.
basal cell carcinoma
Name the micropathology:
basophillic hyperchromatic cells that form nodules, often etending from the surface epidermis
-cells at the periphery of aggregations form a palisade
-tumor nodules are set in a mucinous stroma, w/ retraction from that stroma (clefting)
basal cell carcinoma
what are 3 major risks for getting squamous cell cancer of the skin?
UV light
HPV
immunosuppression
what are the risk factors for the ability of a squamous cell carcinoma in skin to metastasize?
size of tumor (larger than 2 cm clinically greater risk)
depth of invasion into dermis (greater than 4 mm depth, greater risk)
anatomic site (higher risk on lips and ears)
host immune status
what is the most common cause of death in melanoma of the skin?
CNS involvement
what is the most important prognostic factor for melanoma of skin?
lymph node involvement
what are the histologic prognostic factors of melanoma?
breslow thickness & ulceration
what is a keratoacanthoma?
neoplasm of KCs, related to SCC (possibly subtype), grows 2-6 wks
- painful
- may involute spontaneously
what is Marjolin’s ulcer?
ulcerated invasive SCC arising on the background of chronic inflamm. scarring, radiation, trauma
what is the most common type of malignant melanoma in pts with darker skin?
acral lentiginous melanoma
what is a lentigo maligna?
melanoma in situ, slow growing still in radial growth phase (seen in older pts w/ sun-exposed skin)
melanocytes are derived from what kinds of cells?
neural crest cells
where is the most common site for melanocytes to develop into melanoma?
dermal-epidermal junction
what is the #1 organ site for metastasis in melanoma?
SKIN
what is breslow’s thickness?
distance of involvement from the stratum granulosum to the deepest tumor cell (used for melanoma)
about what percent of melanomas have BRAF mutations?
50%
what is the name of the bug that causes american trypanosomiasis (chagas diseae)?
T. cruzi
what is the name of the bug that causes african trypanosomiasis?
T. brucei
How is T. cruzi (chagas disease) transmitted?
REDUVIID BUGS !
what is romana sign?
seen in american trypanosomiasis-edema of the palpebral and periocular tissue due to entry through the conjunctiva
which trypanosomiasis causes trypanosome chancre?
african trypanosomiasis
what is the other name for onchocerciasis?
river blindness
which derm infection can you prevent by not going to Belize?
human botfly (cutaneous myiasis)
The cimicids (bedbugs) have what characteristic finding on the skin?
bites come in 3’s (BREAKFAST, LUNCH AND DINNER)
which type of hair is in the growing phase cycle?
anagen hair (1-5 yrs)
which type of hair is in the resting phase cycle?
telogen hair (3 months)
what should you do when you see pattern alopecia with male pattern distribution in a female pt?
check DHEAS and testosterone
what is the ultimate result of minoxidil treatment?
reverses hair loss and slows the progression of hair loss
who would be the ideal pt where minoxidil would work the best?
young guys
what is androgentic alopecia?
common baldness (gradual miniaturization of hairs w/ transformation of large terminal follicles (visible) to small vellus follicles (invisible)
what is the main adverse effect you have to remember with finasteride?
the sexual side effects could last even if you stop taking the drug
what is telogen effluvium?
an excess shed of telogen hair occurs due to a premature shunting of anagen to telogen
-results in increased shedding of 20-35% of total scalp hair
about how many hairs from the scalp are shed each day?
100
what is anagen effluvium?
acute, extreme alteration of growth of majority of anagen hair
-acute loss of 80-90% of scalp hair (b/c anagen hair makes up a greater %)
what is alopecia areata?
circular area of complete hairloss on a normal scalp
Secondary syphilis has what clinical appearance?
moth-eaten
what is the test for secondary syphilis?
RPR
will the hair grow back if you treat the secondary syphilis?
yes
what are the 3 labs you need to get to exclude other causes of hair loss other than secondary syphilis?
CBC (anemia)
Ferritin (normal CBC and low ferritin, treat w/ iron and get regrowth of hair)
TSH
How can you clinically determine if the hair loss is due to traction alopecia?
look for the peripheral fringe and broken hair
the proximal matrix makes the ________nail plate
dorsal
the distal matrix makes the ______________ nail plate
ventral
fingernails grow about how much each month?
Fingernails-3 mm/month
Toenails-1 mm/month
lichen planus is associated with which disorder that has abnormal nail matrix function?
trachyonychia (sandpaper nails)
which disorder of abnormal nail matrix function has mees’ lines?
true leukonychia
w/ transverse white bands that have been traditionally associated with arsenic and thallium toxicity
Mees’ lines are associated with what abnormal nail matrix function and are associated with what kind of toxicity?
true leukonychia
Arsenic and thallium toxicity
chronic paronychia is most commonly due to what?
candida infection
recurrent episodes of acute paronychia should raise concern for what kind of infection?
HSV infection
which type of onychomycosis is associated with immunosuppression/HIV?
proximal subungual (PSO)
what is the most frequent tumor of the nail apparatus?
squamous cell carcinoma
what is the main causative role of squamous cell carcinoma when it involves the nail apparatus?
HPV16
Hutchison’s sign is found in what nail pathology?
melanoma
hutchison’s sign =extension of pigment onto the nail folds
How can you tell if a certain rash come from the outside?
outside origin= scaley red thickened skin, straight lines, geometric shapes, spares folds
how can you tell if a rash has an internal origin?
flat, doesn’t spare folds, no straight lines, no sharp cutoffs
what kinds of things can cause an internally originating rash?
drugs
Rocky mountain spotted fever
meningococcemia
hepatitis
what kinds of things cause an external origin rash?
contact dermatitis
describe what older skin on sun exposed area looks like?
thinner, dryer, scaley, bruises more easily
Name the pathology:
very common benign lesion that’s tan w/ pigmented waxey plaques, looks like someone threw mud against a wall (stuck on appearance)
seborrheic keratosis
Name the lesion: benign red papules and nodules made up of blood vessels
cherry angiomas
name the lesion:
dome shaped nodule usually with a hyperpigmented border, feels like a BB under the skin
dermatofibroma
name the lesion:
large blue vascular lesion on the lower lip, compressible, benign
venous lake
name the lesion: keratotic horn shaped projection produced by multiple causes such as warts, seborrheic keratoses, and squamous cell carcinoma, must biopsy base for diagnosis
cutaneous horn
name the pathology:
due to lower leg swelling the lower leg is scaley and red, diagnose pitting edema, progression from scaley red to erosionsto ulcers if no treatment
stasis dermatitis
term for flat discolored spot on skin not raised above the surface
macular
term for a small blister that contains serous fluid
vesicle
term for a pus filled blister
pustule
term for a large bump greater than 4mm
nodule
term for a small bump less than 4 mm
papule
term for a well defined elevated are of skin
plaque
Name the pathology:
scaley red macules, papules or plaques commonl seen on the elbows and knees
psoriasis
name the pathology:
red scaley rash found on posterior neck, popliteal and antecubital fossae
atopic dermatitis
name the pathology:
multiple scaley red oval plaques commonly begins with a single lesion (herald patch) and then days to wks later multiple lesion develop, lesions are in cleavage lines and have a christmas tree distribution?
pityriasis rosea
Name the pathology:
scaley rough lesions on long term sun exposed skin (1/1000 turn into squamous cell carcinoma)
actinic keratosis
Name the pathology:
round pearly lesions with telangiectasias due to long term sun exposure spreads wide and deep but rare to metastasize
basal cell carcinoma
Name the pathology:
keratotic nodule with firm base which usually begins as an actinic keratosis and becomes a neoplasm.
squamous cell carcinoma
what are the ABCDs of melanoma?
asymmetry
borders (irregular)
color (variations)
diameter (greater than 6 mm)
what do you do if a pt comes in and says that their mole has changed?
take it off
increased educational status correlates with increased risk of developing what?
melanoma
what are the clues that let you know a rash is getting better?
redness (if redness decreases)
Desquamation (skin peels off)
Wrinkling (swelling and inflammation have gone down)
always examine a pt with their clothes _______
OFF
what would a biopsy of an outside origin rash look like?
abnormal stratum corneum, inflamm. cells, in the epidermis and sometimes blister, clinically looks like red scaley skin + blister
what would a biopsy of an internal origin rash look like?
scattered inflammatory cells in the dermis, clinically this looks red, the epidermis is unaffected clinically flat and smooth
which rash presents in a classic dermatome pattern?
herpes zoster
Name the pathology:
group of blisters on a red base
herpes
if you have a pt who comes in with lesions on their palms and soles you should start thinking about what?
secondary syphilis
term for a special group of exotoxins that bind conserved portions of T cell receptors and are able to activate a large number of T lymphocytes.
superantigens
which 2 microbes classically make the superantigens?
Staph aureus & Strep pyogenes
Term for a superficial crusting epidermal skin infection that presents in bullous and nonbullous forms. Often has a honey crusted coating
impetigo
when you see a young honey colored crusting epidermal skin infection on a kid’s face you know he has what?
impetigo
term that describes the superficial infection of hair follicles with pus accumulation in the epidermis.
folliculitis
term for the streptococcal infection of the superficial dermal lymphatics that demonstrates sharply demarcated, raised borders.
erysipelas
term for fungi that digest keratin as their nutrient source?
dermatophytes
95% of tinea pedis cases are caused by ___________
dermatophytes
jock itch is caused by what?
tinea cruris
ring worm is caused by what?
tinea corporis
tinea facei
candidiasis is more common in which pts?
women (accounting for vulvovaginal candidisis, and in immunosuppressed pts)
Most common form is herpes infection is________________ presents as vesicular or ulcerative lesions of the oral cavity or perioral skin and mucosa (HSV-1)
herpes labialis
term for HSV superinfection of atopic dermatitis
eczema herpeticum
Name the lesion: painful grouped vesicles on an erythematous base on the border of the lip.
HSV-1 herpes labialis
name the pathogen: “dew drops on a rose pedal”
varicella chickenpox
name the pathology:
produces a painful prodrome, followed by a dermatomal vesicular eruption
zoster rash (varicella zoster virus) aka shingles
Name the pathogen:
multinucleated acantholytic keratinocyte under histopathology
herpetic viral infection
name the pathology:
pearly white umbilicated papules in a child
molluscum contagiosum (caused by DNA pox virus)
90% of genital warts are caused by what 2 viruses?
HPV6 & HPV11
which 2 viruses are strongly associated with cervical cancer?
HPV16 & HPV18
Gardasil covers which HPV types?
6, 11, 16, 18
Cervarix covers which HPV types?
16, 18 (cervical cancer)
defects in the development of the ectoderm lead to what?
ectodermal dysplasia
ichythosis vulgaris is due to what kind of mutation?
filaggrin
what embryonic tissue forms the epidermis?
only the ectoderm
what embryonic tissue forms the dermis?
ectoderm and mesoderm
what is stasis dermatitis?
due to venous insufficiency and edema (can result in venous ulcers)
what are the 2 most important treatments of stasis dermatitis?
ELEVATION & COMPRESSION
Is there a vaccine for ParvoB19?
“NO VACCINE FOR PARVOB19”
what is the cause of hand-foot-mouth disease?
coxsackie virus
If you see a pt with eczema herpeticum in the derm clinic what do you need to do?
SEND THEM TO THE ER!
superficial fungal infections only hit what kind of tissue?
dead keratinous tissue
what is a histologic clue that there is a superficial fungal infection?
neutrophils in the stratum corneum
Name the pathogen:
vacuolated superficial keratinocytes w/ pyknotic raisin-like nuclei (koilocytes)
HPV
name the pathogen: multinucleated keratinocytes
herpes viruses
name the pathology: sunburn-like erythema and sandpaper papules
TSS
which virus causes immunosuppression by infecting lots of monocytes?
measles
albinism is due to a lack of what?
melanin
what is the follicular occlusion tetrad?
- acne conglobata
- Hidradenitis suppurativa
- Dissecting Cellulitis
- pilonidal cyst
Pellagra is caused by what kind of deficiency?
niacin
what are the 3 D’s of pellagra?
Dementia
Dermatitis
Diarrhea
hypohidrotic ectodermal dysplasia is dysfunction in thermoregulation with a mutation in what gene?
EDAR-ectodyplasin A receptor
- unable to regulate temp.
- results in abnormal hair follicles, sweat lands and teeth
stratum corneum compared to brick and mortar, what are the bricks and whats the mortar?
bricks=flattened keratinocytes filled w/ keratin & filaggrin
mortar=lipid mixture surrounding keratinocytes (water barrier)
the keratins combine to form ______________filaments
intermediate
what is the primary cell in the dermis?
fibroblast
fibroblasts have what kind of origin?
mesenchymal
what are apocrine sweat glands?
sweat glands that are associated with a hair follicle (found in axilla and anogenital skin)
what are eccrine sweat glands?
sweat glands not associated hair follicle (all over body)
what are sunburn cells?
damaged keratinocytes that are undergoing apoptosis
what happens if you fail to delete the cells damaged by the sun?
could cause cancer
In what layer of the epidermis is profilaggrin processed into filaggrin?
stratum corneum
atopic dermatitis is assoicated with genetic defects in what gene?
filaggrin
what is a nevus?
aka mole, benign collection of melanocytes
what are some of the histological changes with sunburn?
damaged keratinocytes (sunburn cells inflamm. intercellular edema perivascular edema hyperkeratosis, acanthosis (after 72 hours)
what is chronologic aging?
smooth, pale finely wrinkled skin with benign growths
what is photoaging?
dry deeply wrinkled inelastic leathery atrophic, telangiectasias, irregular pigmentation
what another name for freckles?
ephelides
how do melanomas metastasize?
lymphatics
onycholysis (distal nail plate detachment from the nail bed) is commonly to due what 2 things?
PSORIASIS
or onychomycosis
splinter hemorrhages in the nail bed are most commonly associated with what?
bacterial endocarditis
What is the prognosis of erythema toxicum neonatorum?
benign, up to 50% of infants, resolves spontaneously
when do keratinocytes present antigen?
when they are stimulated
pemphigus vulgaris often starts with ____________________
mucosal erosions (more likely to see erosions rather than blisters)
what is the prognosis for untreated pemphigus vulgaris?
high mortality (30-70%)
pemphis vulgars has autoantibodies against which antigen?
desmoglein 3 (PVDG3)
Describe the clinical presentation of bullous pemphigoid?
fairly sudden onset of very itchy wheals and tense blisters on trunk and extremities (mouth and oral mucosa affected in some)
which drug can cause bullous pemphigoid?
furosemide
In bullous pemphigoid there are autoantibodies against which antigens?
BPAg1
BPAg2
