Greg Larsen - Derm Review Flashcards
what is pediculosis
lice
how are pediculosis transmitted
through direct contact or fomites
can pediculosis jump/fly
no!
sx of pediculosis
constant itching
+/- eczema or lichen simplex chronicus
what do these heads have?
pediculosis
can look like eczema
first line tx for pediculosis according to CDC
permethrin 1% lotion
brand name for permethrin
Nix
what do you think when you see: burrows or s shaped erythematous tracts on the skin in inertriginous zones
scabies
who is at risk for scabies
houseolds/communities w. close intimate contact and overcrowding
sx of scabies
intense itching
can be worse at night
what do these people have
scabies
what question should you ask a patient w. suspected scabies
are any family members or close contacts experiencing sympsoms?
tx for scabies
permethrin cream and another application 1 week later
2 skin and soft tissue infections that are commonly associated w. erythema, edema, pain
cellulitis
erysipelas
deeper infection involving the dermis and subcutaneous tissue
cellulitis
superficial skin infxn involving lymphatic streaking
erysipelas
cellulitis and erysipelas are mc caused by
GAS
s. aureus
H.flu
erisypelas is commonly seen on the
face
what does this person have
erisypelas
what does this person have
cellulitis
cellulitis is commonly seen on the
legs
cellulitis and erysipelas are commonly missed; what is the ddx for these conditions
stasis dermatitis
eczema
DVT
osteomyelitis
ulcerations
pressure sores
fungal infxns
intertrigo
erythrasma
whether or not cellulitis and erysipelas are purulent, you should
drain and culture!
always!
gold standard op empiric tx for cellulitis and erysipelas
cephalexin (keflex)
what is the more realistic op tx for cellulitis and erysipelas
doxycycline
bc it covers MRSA
tx for hospitalized pt w. cellulitis/erysipelas
IV abx → ex Vanco
“pathetic version of cellulitis”
impetigo
what do you think when you see “tiny fragile yellow to honey colored crusted vesicles”
impetigo
mc pathogens associated w. impetigo
s.aureus
streptococcus pyogenes
what does this kid have
impetigo
impetigo can also present as
small fluid filled vesicles that crust over after the bullae ruptures
what do these kids have
impetigo
tx for localized/limited impetigo
topical mupirocin
does topical mupirocin cover mrsa
yes!
tx for widespread/non responding impetigo
doxycycline
only for kids >8 yo
not for pregnant
what do you think when you see: mild exanthem that is generally self resolving; slapped cheek rash followed by rash over cheset, back, buttocks, extremities
erythema infectiosum
erythema infectiosum is same-same
parvovirus
5th disease
what does this kid have
erythema infectiosum (parvovirus)
primary cause of transient aplastic crisis
erythema infectiosum (parvovirus)
what do you think when you see: coxsackievirus A 16 and enterovirus 71
hand-foot-and-mouth dz
what does this kid have
hand food mouth dz
how does hand food mouth dz present
vesicular palmoplantar eruptive rash
is this hand food mouth dz
no! it is syphilis
always be wary of vesicles on the
palms and soles
what does this person have
measles (rubeola)
contagious viral exanthem via droplet spread and direct contact; single stranded RNA morbillivirus
measles (rubeola)
prodrome of measles (3)
cough
coryza/rhinitis
conjunctivitis
2 classic signs of measles
nose and eyes run continuously
koplik spots
what are koplik spots
blue to white lesions with a red halo
what are these
koplik spots → blue to white lesions with a red halo
rare group of blistering AI disorders that tend to involve skin and mucosal membranes
pemphigus
what do you think when you see desmoglein antibodies Dsg1 and Dsg3
pemphigus
what is desmoglein
adhesion molecule that helps keep structural integrity to the epidermis
what does this person have
pemphigus
mc/dominant form of pemphigus
pemphigus vulgaris
how does pemphigus vulgaris present
painful oral erosions
what do you think when you see: exceptionally brittle bullae/blisters; positive nikolsky sign
pemphigus vulgaris
what is nikolsky sign
sloughing of epidermal tissue w. pressure
what does this patient have
pemphigus vulgaris
shallow erosions/abrasions w. erythema and scaling
+/- blister formation
pemphigus foliceus
what does this patient have
pemphigus foliaceus
dx for pemphigus
perilesional punch bx w. skin adjacent to blister
what do you think when you see Michel’s medium
direct immunofluorescence (DIF) for pemphigus
Michel’s medium helps to
improve shelf life of processing tissue
tx for pemphigus
no official clear tx guidelines
reduce inflammatory response w. immunosuppressants → prednisone
mc AI blistering skin dz
bullous pemphigoid
bullous pemphigoid is considered a dz of
advanced age
60 yo +
what does this pt have
bullous pemphigoid
how does pemphigoid present
localized erythema or urticarial plaques that worsen over time → hives
how do blisters of pemphigoid differ from pemphigus
pemphigoid blisters appear more structurally intact → negative nikolsky sign
rubbing of skin results in sloughing of epidermal tissue
nikolsky sign
nikolsky sign is positive in __
and negative in __
pemphigus
pemphigoid
what does this pt have
pemphigoid
dx for pemphigoid
perilesional punch bx w. skin adjacent to blister
DIF including michel’s medium is used for
pemphigus
AND
pemphigoid
initial serum tests for pemphigoid
BP 180
BP 230
mainstay tx for pemphigoid (and pemphigus)
prednisone
common acute and recurrent inflammatory/hypersensitivity dz that often follows viral infxn/bacterial infxn or in pregnant pt
erythema multiforme
what do you think when you see: targetoid lesions often on extremities, hands, feet
erythema multiforme
pathology of erythema multiforme involves
immune complexes
erythema multiform often presents w. __ targetoid lesions
uticarial
what do these patients have
erythema multiforme
tx for erythema multiforme
self limiting
+/- prednisone
immune complex mediated desquamative hypersensitivity d.o; extreme form of erythema multiform
stevens-johnson syndrome/toxic epidermal necrolysis (TEN)
__ are almost always involved in stevens johnson syndrome
oral mucosa → lips
stevens johnson is mc seen in what 2 pt pops
kids
young adults
what do these patients have
stevens johnson syndrome
primary dx test for Stevens Johnson syndrome
punch bx
epidermal necrosis and apoptosis of keratinocytes
punch bx finding for stevens johnson
in stevens johnson, nikolsky sign will be
positive
tx for stevens johnson
d/c meds!
admit to burn unit
fluid/lytes
wound care
consult all the specialists
what pharm is contraindicated in stevens johnson
oral steroids
pigmentation d.o frequently associated w. pregnancy and women taking OCP
melasma
melasma frequently appears on the
forehead
molar cheeks
upper lip
chin
acquired loss of pigmentation
vitiligo
who is this?
michael jackson duh!
he has vitiligo
flat hypopigmented 2-5 mm macules in sun exposed areas
idopathic guttate hypomelanosis
what does this patient have
idiopathic guttate hypomelanosis
hair loss on any are of the body where hair would normally be present
alopecia
alopecia is divided into
scarring/cicatricial
non-scarring
scarring alopecias
central centrifugal cicatricial alopecia
lichen planopilaris
frontal fibrosing alopecia
dissecting cellulitis
acne keloidalis nuchae
non scaring alopecias
alopecia areata
traction alopecia
genetic pattern hair loss
telogen effuvium
central scarring alopecia that spreads outward
central centrifugal cicatricial alopecia
what does this patient have
central centrifugal cicatricial alopecia
type of alopecia that presents w. patchy erythema and perifollicular scarring on the front-central scalp and crown
lichen planopilaris
what does this patient have
lichen planopilaris
lichen planopilaris should make you consider
syphilis
is lichen planopilaris painful?
yes → pain, stinging, burning in active areas
exam of scalp shows spinous hyperkeratotic follicular papules w. perifollicular erythema
lichen planopilaris
what does this pt have
lichen planopilaris
variant of lichen planopilaris that involves hair loss in other locations (eyebrows/upper extremities)
frontal fibrosing alopecia
what does this pt have
frontal fibrosing alopecia
patchy pustular eruptions of the scalp; chronic in nature; leads to inflammation and permanent scalp scarring
folliculitis decalvans
what does this pt have
folliculitis decalvans
wide spread folliculitis w. atrophic patchy scarring and perifollicular crusts
folliculitis decalvans
mechanical form of folliculitis/inflammation which causes scarring alopecia; typically affects darker skinned men w. curly hair
acne keloidalis nuchae
what does this pt have
acne keloidalis nuchae
asymptomatic loss of complete hair in one or more patches of any hair bearing surface
alopecia areata
what does this pt have
alopecia areata
3 types of alopecia areata
areata
totalis
universalis
alopecia areata
partial hair loss
alopecia totalis
100% hair loss of scalp
alopecia universalis
100% hair loss of whole body
what is this and what does it make you think of
exclamation point hairs
alopecia areata
what are exclamation point hairs
broader/wider distal shaft and narrow proximal shaft/base
alopecia 2/2 to prolonged mechanical tension like grooming and styling
traction alopecia
what does this pt have
traction alopecia
androgenetic alopecia in men that is a physiologic response 2/2 to androgens
genetic patterned hair loss
what do you think when you see hamilton patterns
classification for genetic patterned hair loss
tx for genetic patterned hair loss
minoxidil, finasteride (rogaine)
temporary shedding brought on by stimulus → ex stress
telogen effluvium
inflammation of nailfold tissue; usually infectious
paronychia
what do you think when you see chronic paronychia w. green nail
pseudomonas
chronic paronychia is > __ weeks
6
what is this
green nail syndrome/chloronychia
pseudomonas
fungal infxn of the nails
onychomycosis
4 types of onychomycosis
distal subungual
white superficial
proximal subungual
candida onychomycosis
white superficial onychomycosis typically requires __ for dx
oral tx rather than topical → itraconazole, fluconazole, terbinafine
mc type of onychomycosis
distal subungual
type of onychomycosis seen in immunocompromised pt
proximal subungual onychomycosis
candida onychomycosis is caused by
candida albicans
candida onychomycosis generally involves
all the fingernails
what does this pt have
onychomycosis
oral med for onychomycosis that can cause liver dz
terbinafine