Dermatology Flashcards
blistering diseases
pemphigus vulgaris
bullous pemphigoid
dermatitis herpetiformis
porphyria cutanea tarda
pemphigus vulgaris path
anti-desmoglein antibodies = desmosomes
intra-epithelial lesions
pemphigus vulgaris pt
thin, easily torn blisters (+ Nikolsky)
INVOLVES mucosa
age 30-50
pemphigus vulgaris dx
biopsy showing tombstoning
immunofluorescence shows intra-epithelial pattern, surround cells
pemphigus vulgaris tx
acute, life-threatening = IVIG
acute, not life-threatening = steroids
chronic = mycophenolate or rituximab
bullous pemphigoid path
anti-hemidesmosome antibody
sub-epidermal lesion
bullous pemphigoid pt
tense, rigid bull (- Nikolsky)
no mucosa
age 70-80
bullous pemphigoid dx
biopsy intact epithelium detached from basement membrane
immunofluorescence shows antibodies at dermal-epidermal junction
bullous pemphigoid tx
steroids
- topical for limited
- systemic for severe
mild: dapsone + nicotinamide
dermatitis herpetiformis path
deposition disease, papillae
IgA anti-transglutaminase
cutaneous manifestation of celiac sprue
dermatitis herpetiformis pt
palpable pruritus rash on extensor surfaces and buttocks
dermatitis herpetiformis dx
anti-transglutainase, anti-endomysial
EGD = smooth vili
biopsy not needed = neutrophilic abscess
dermatitis herpetiformis tx
remove gluten from diet
temporize with dapsone
porphyria cutanea tarda path
most common porphyria
uroporphyrin decarboxylase deficiency
accumulation of uroporphyrins
porphyria cutanea tarda pt
bull on sun-exposed lesions
porphyria cutanea tarda dx
coral red urine under WOod’s lamp
24hr urine collection for uroporphyrins
porphyria cutanea tarda tx
avoid the sun
porphyria cutanea tarda f/u
look for hemochromatosis, HepC, EtOH, and OCPs
papulosquamous dermatoses
seborrheic dermatitis
psoriasis
pityriasis rosea
lichen planus
seborrheic dermatitis path
fungal infection
‘dandruff plus’
seborrheic dermatitis pt
rash and flakes seen on scalp and eyebrows, hair-bearing regions only
seborrheic dermatitis dx
clinical
seborrheic dermatitis tx
selenium shampoo
seborrheic dermatitis f/u
HIV, cradle cap, Parkinson’s
psoriasis path
autoimmune disease, helper T cells
excess stratum corneum
psoriasis pt
symmetric, well-demarcated patches with silvery scales that bleed when picked
nail pitting, onycholysis (nail detachment)
psoriasis dx
clinical (may biopsy to r/o lymphoma)
psoriasis tx
1st: UV light
alternative: topical steroids (use sparingly)
flare: oral steroids
recalcitrant: immune modulators such as tacrolimus
psoriasis f/u
joint pain, seronegative spondyloarthropathy
pityriasis rosea path
benign, self-limiting, idiopathic
pityriasis rosea pt
flat oval-shaped salmon-colored macule (hyperpigmentation in dark skin)
scaling lesion that does not reach the border (trailing scale)
pityriasis rosea dx
RPR to r/o syphilis, pityriasis is clinical
pityriasis rosea tx
non, self-limiting
pityriasis rosea f/u
if on palms and soles, syphilis likely, should normally spare palms and soles
lichen planus path
inflammatory, idiopathic
lichen planus pt
intensely pruritic pink/purple flat-topped papules with a reticulated network of fine white lines
wrists and ankles common, can be in mouth or vagina
lichen planus dx
clinical
lichen planus tx
topical steroids (first line) UV light (adjunct) oral steroids (severe) immune modulators (recalcitrant)
lichen planus f/u
drug induced from ACE-i, thiazides, loops
eczematous dermatoses
atopic dermatitis
contact dermatitis
stasis dermatitis
hand dermatitis
atopic dermatitis path
immune reaction to allergens or foods
atopic dermatitis pt
adult: symmetric lichenification wherever the patient can reach to scratch
child: dry, red, itchy rash on cheeks and extensor surfaces, look for asthma and allergies along with atopy
atopic dermatitis dx
clinical
atopic dermatitis tx
avoidance of triggers (remove foods)
topical steroids for adult (brief use)
contact dermatitis path
hypersensitivity type IV reaction
latex, nickel, poison ivy
contact dermatitis pt
well-demarcated red rash in the shape of an object or clothing
pruritic, raised, and red
contact dermatitis dx
clinical
contact dermatitis tx
avoid contact with triggers
topical steroids
stasis dermatitis path
skin changes associated with edema
stasis dermatitis pt
edema in an extremity, chronic
brownish discoloration, erythema, scaling at site of edema
stasis dermatitis dx
clinical
stasis dermatitis tx
get the fluid out of the extremity with either diuretics if overloaded or compression stockings/leg elevation
hand dermatitis path
dermatitis isolated to the hands in someone who washes their hands a lot or deals with chemicals
hand dermatitis pt
food-service worker, healthcare worker
hand dermatitis dx
clinical
hand dermatitis tx
moisturizers and avoidance of harsh soaps
hypersensitivity reactions
urticaria drug reaction erythema multiform stevens-johnson syndrome toxic epidermal necrosis staphylococcal scalded skin syndrome
urticaria path
type I hypersensitivity
IgE induced mast cell degranulation -> histamine release = leaky capillaries
urticaria pt
annular, blanching red papule following any antigen exposure (bee stings, heat, pressure, medication)
urticaria dx
clinical
urticaria tx
antihistamine
urticaria f/u
send for RAST to identify culprit antigen
urticaria f/u
if anaphylaxis, give subQ epi, f/b steroids, H1-blocker and H2-blocker
- epi is crucial and is first
drug reaction path
autoimmune
drug reaction pt
pink morbilliform rash occurring 7-14d after drug exposure, usually in hospitalized patients
if day 2-3 after drug, that ISN’T the cause
wide-spread, symmetric, and pruritic
drug reaction dx
clinical
drug reaction tx
remove offending agent
diphenhydramine for mild symptoms
corticosteroids for severe symptoms
erythema multiforme path
drug-reaction, HSV reaction
erythema multiforme pt
targetoid lesions that appear on palms and soles
erythema multiforme dx
clinical
erythema multiforme tx
Acyclovir if HSV related
self-limited otherwise
erythema multiforme f/u
if involving the oral mucosa, it is considered erythema multiforme major, and is SJS spectrum
erythema multiforme f/u
syphilis can also present with targetoid lesions on palms and soles
stevens-johnson syndrome/toxic epidermal necrosis path
drug reaction
stevens-johnson syndrome/toxic epidermal necrosis pt
+ nikolsky and oral involvement
BSA: <10% SJS z> 30% TENS
stevens-johnson syndrome/toxic epidermal necrosis dx
biopsy
- SJS = basal cell degeneration
- TENS = total epidermal thickness necrosis
stevens-johnson syndrome/toxic epidermal necrosis tx
admit to burn unit, supportive care
NO steroids
withdraw all medications
staph scalded skin syndrome path
intraepidermal lesions from staph toxin targeting desmoblein (desmosomes)
staph scalded skin syndrome pt
NO mucosal involvement
febrile, sloughing of skin, skin folds first off the axillae and inguinal creases
staph scalded skin syndrome dx
biopsy
staph scalded skin syndrome tx
clindamycin (stop toxin production)
hyperpigmentation
nevus seborrheic keratosis actinic keratosis squamous cell carcinoma keratoacanthomas kaposi's sarcoma
nevus path
benign hyperplasia of melanocytes
nevus pt
raised, painless, pigmented lesion that has none of the ABCDE
if hair-bearing, it is benign
nevus dsx
ABCDE... any one means malignancy Asymmetric Border irregularity Color mixed Diamter large (>5mm) Evolving over time
nevus tx
wide excisional biopsy if you think melanoma
leave it alone if all ABCDE are negative
seborrheic keratosis path
looks like cancer, but isn’t
seborrheic keratosis pt
large, brown, greasy, ‘stuck on’ lesions
seborrheic keratosis dx
clinical
seborrheic keratosis tx
leave it alone
seborrheic keratosis f/u
biopsy if changing, if not changing, leave it alone.
it could be cancer if it is changing
actinic keratosis path
premalignant lesion
squamous cell carcinoma in the making
actinic keratosis pt
sun-exposed area (hands, face, back)
sun-exposed person (sailor, farmer)
erythematous with sandpaper-like yellow to brown scale
actinic keratosis dx
biopsy
actinic keratosis tx
primary prevention is key
cryosurgery if small lesion
5-FU if diffuse
squamous cell carcinoma path
actinic keratosis -> carcinoma in situ -> invasive carcinoma (DOES metastasize)
squamous cell carcinoma pt
sun-exposed areas sun-exposed person lesion on the lower lip dark lesion on the face, hands, back ulcers taht fail to heal (Marjolin's ulcer)
squamous cell carcinoma dx
biopsy
squamous cell carcinoma tx
surgical resection
keratoacanthomas path
benign lesions that look like SCC
keratoacanthomas pt
they have SCC except it grew rapidly and then resolved spontaneously
keratoacanthomas dx
surgical resection
keratoacanthomas tx
surgical resection
kaposi’s sarcoma path
malignancy of vascular endothelial cells
AIDS (CD4 <200) and HHV-8 coinfection
kaposi’s sarcoma pt
purple lesions that can be literally anywhere, mouth, arms, intestines
kaposi’s sarcoma tx
HAART, treat AIDS, this gets better
kaposi’s sarcoma f/u
local or systemic chemo may be needed in refractory cases (do not learn chemo)
hypopigmentation
tinea versicolor
vitiligo
albinism
ash leaf
tinea versicolor path
infection with the fungus Malassezia furfur
tinea versicolor pt
small scaly patches of hyper and hypopigmentation
tinea versicolor dx
KOH prep = spaghetti and meatballs, actually hyphae and spores
tinea versicolor tx
selenium sulfide
vitiligo path
autoimmune disease
vitiligo pt
sharply demarcated, small patches of depigmented skin, often on face, hands, and genitalia
vitiligo dx
Wood’s lamp shows NO pigment
biopsy = absence of melanocytes
vitiligo tx
none
cosmetics
- bleaching to lighten uniformity
- dyes/makeup to darken uniformity
albinism path
tyrosinase deficiency
albinism pt
pale skin, pale eyes, pale hair
albinism dx
clinical
albinism tx
supportive, avoid UV light
albinism f/u
PKU has funny smell, intellectual disability, seizures in addition to pale skin and fair hair
screened for at birth
ash leaf path
hypo pigmented (NOT depigmented)
ash leaf pt
child, hypopigmented
ash leaf dx
Wood’s lamp = ash leaf
CT scan head = tubers
ash leaf tx
nothing can be done about tuberous sclerosis
supportive care
skin infections
impetigo
erysipelas
acne vulgaris
impetigo path
infection with Strep pyogenes
infection with Staph aureus (bullous)
impetigo pt
child
honey-crusted lesions on face
impetigo dx
clinical
impetigo tx
local disease = muprocin
lots of disease = amoxicillin (strep)
refractory = clindamycin (staph)
impetigo f/u
can cause post-strep glomerulonephritis
canNOT cause rheumatic fever
erysipelas path
infection of strep in lymphatics
erysipelas pt
dark red, clearly defined lesion in the shape of lymphatics (tracks or lines)
erysipelas dx
clinical
erysipelas tx
ß-lactams, amoxicillin (strep)
acne vulgaris path
propionibacterium acnes
acne vulgaris pt
zits, acne
acne vulgaris dx
clinical
acne vulgaris tx
comedones = topical retinoids
inflamed comedone = topical retinoids and benzoyl peroxide
severe pustular = oral abx (doxy)
resistant disease = isotretinoin
acne vulgaris f/u
UPT before isotretinoin (teratogen)
alopecia
alopecia areata trichotillomania tinea capitis traction alopecia chemo male-pattern baldness
alopecia areata path
autoimmune disease
well-defined circular bald spot
alopecia areata pt
may include entire body
exclamation point sign
alopecia areata dx
clinical, r/o tinea capitis if in question
alopecia areata tx
steroids
trichotillomania path
compulsive disorder (OCD, PTSD, MDD)
trichotillomania pt
patchy alopecia
hair in different lengths of growth
women
trichotillomania dx
clinical, can use a ‘window’
trichotillomania tx
treat the psychiatric disease
tinea capitis path
fungal infection, trichophyton tonsurans
tinea capitis pt
well-defined circular bald spot
all hairs at equal length
tinea capitis dx
KOH prep
tinea capitis tx
oral antifungals (griseofulvin) hair loss permanent if not treated
traction alopecia path
scarring from pulling hair tightly
traction alopecia pt
tight braiding, ponytails
hair loss is preventable, but irreversible
traction alopecia dx
clinical
traction alopecia tx
none
chemo path
chemo targets rapidly dividing cells
chemo pt
patients can lose their hair during chemo
clinical
chemo dx
none
chemo tx
none
male pattern baldness path
5DHT (androgen) driven loss of hair
male pattern baldness pt
crown thins, then loses hair
rest of hair on top of head then follows
male pattern baldness dx
clinical
male pattern baldness tx
1st minoxidil topical
best minoxidil topical and finasteride oral
woman = OCPs and spironolactone