Dermatology Flashcards
Cradle cap
dz: Seborrheic dermatitis
path: malassezia furfur
CP: itchy, flaky/scaly, greasy, yellowish
tx: mineral oil to scalp (infants)
selenium sulfide shampoo (teens)
What is the treatment for seborrheic dermatitis?
infants: mineral oil
teens: selenium sulfide shampoo
Diaper dermatitis
contact dermatitis
CP: SPARES inguinal folds (DDx: Candida - affects inguinal folds)
Tx: avoid irritant, keep skin surface dry, use emollients
What is the DDx for diaper dermatitis?
Candida
CP: satellite lesions, “beefy red” rash, affects inguinal folds
Tx: TOP antifungal (fluconazole, nystatin)
Perioral dermatitis
eti: can be triggered by steroid creams/ointments, cosmetics
CP: small red bumps around mouth +/- nose, cheeks, eyes
tx: TOP Abx, +/- top steroids
What is the treatment for perioral dermatitis?
avoid triggers/cosmetics
topical abx +/- top steroids
What is the most common type fo cutaneous drug reactions?
exanthematous eruptions (delayed)
What does the rash look like for drug eruptions?
starts on trunk, spreads to face/extremities
What is the treatment for drug eruptions?
stop drug
rash will clear 2-3 days after drug is stopped
5Ps
lichen planus
purple, pruritic, polygonal, planar, papules/plaques
What is the treatment for lichen planus?
top steroids (mod - strong)
White, lacy, reticular lesions
oral lesions (Wickham striae) lichen planus of the mouth
Herald patch
seen with pityriasis rosea
typically on trunk w/ scaling
follows langer’s lines (Christmas tree)
lasts between 4-10 weeks
rare in children <3-4 yo
SATAN
high risk drugs seen with SJS/TENS
sulfa drugs allopurinol tetracyclines AEDs (carbamazepines, lamotrigine, pheytoin) NSAIDs Nevirapine
SJS/TEN
mucocutaneous reaction
type 4 HSR
<10% BSA = SJS
>30% BSA = TENs
CP:
onset within 8 weeks - rapid progression
prodrome (fever, malaise, flu-like sxs)
Begins on face/trunk, spreads outward
Nikolsky sign - sloughing - detachment of epidermis
Mucosal membrane involvement in >90% of cases
sub-epidermal cleavage –skin biopsy
tx: supportive treatment
Which type of HSR is SJS/TENs?
4
CP of SJS/TENS?
onset within 8 weeks - rapid progression
prodrome (Fever, malaise, flu-like sxs)
begins on face/trunk – spreads outward
Nilkolsky sign - sloughing - detachment of epidermis
Mucosal membrane involvement in >90% of cases
Sub-epidermal cleavage - skin biopsy
SSSS
path: exotoxin in staph aureus causes breakdown in desmosomes and detachement within epdiermal layer
CP: exofloiative rash, flaccid bullae, skin desquamation
Recent URI
starts on face (perioral), neck, spreads to axillae and groan
Erythema mutliforme
eti: thought to be hypersensitivity to virus (HSV, mycoplasma)
half of all cases occur <20yo
CP: target lesion (3 zones = dark center, pale inner ring, red outer ring)
exanthem - starts on distal extremities and spreads proximally
EM minor: confined to extremities and face (no mucous membrane involvement)
EM major: affects extensive surface area, bullous lesions
self limited: resolves in 2 weeks
What is the most common etiology of erythema multiforme?
HSV
Erythema multiforme rash and distribution
Target or Iris lesions - round shape with 3 concentric zones
dark center, pale inner ring, red peripheral outer zone
distal extremities and spreads proximally
What is drug induced hypersensitivity syndrome?
skin eruption with systemic sxs + internal organ involvement
What is serum sickness?
immune complex (type 3) occurs after animal proteins or serum or drugs
How does serum sickness present?
rash, joint pain, fever
erythema occurs on sides of fingers, toes, hands
Black dot alopecia
tinea capitis
infection of scalp and hair shafts
What is the treatment for tinea capitis?
griseofluvin
selenium sulfide shampoo
T. Rubrum
tinea corporis
What is the tx for tinea corprois?
local miconazole or clotrimazole
Tinea cruris
jock itch
spares the scrotum
tx: local miconazole or clotrimazole
Tinea unguium
onchyomycosis
peeling of distal nail plate
What is the tx for onchyomycosis?
oral ketoconazole or griseofluvin
Spaghetti and meatballs
tinea versicolor on KOH prep
M. furfur
tinea versicolor
How can you tell the difference b/w diaper dermatitis and candida infection?
skin fold are only involved in candida infections
should suspect is > 3 days
beefy red erythema with satelite lesions
What is the treatment for diaper dermaititis?
open air exposure
topical zinc oxide
1% hydrocortsione (use < 2 weeks)
How do you tx perioral dermatitis?
topical metronidazole or erythromycin
spares vermillion border
Atopic triad
Eczema + allergic rhinitis + asthma
T cell mediated immune reaction
Where is atopic dermatitis in infancy?
on the face
as opposed to adolesence where its on flexor surfaces
Milia
keratin filled papules found on the face - without erythema
often confused with sebaceous hyperplasia
Sebaceous gland hyperplasia
maternal androgen - similar to neonatal acne
regression occurs when hormone levels decline
“hormones leaving the body”
Neonatal acne
sebaceous gland blockage
peaks around 2 weeks of age and resolves with a decline in maternal hormones in 3-4 months
M. furfur
tinea versicolor
AND
seborrheic dermatitis
CRADLE CAP - yellow/pink greasy appearing scales on scalp and erythematous scaling on neck and face
What is the treatment for cradles cap?
ketoconazole 2% cream/shampoo 2x/wk
When does SJS or TEN present?
within 8 weeks of exposure to drug
What is the difference between SJS and TEN?
SJS <10% of BSA
TEN >30% of BSA
What is the treatment for acne in adolescence?
Mild: Topical ABX and benzoyl peroxide
Moderate: benzoyl peroxide + tretinoin + topic ABX
Severe: Oral ABX or accutane (isotretinoin)
What is the most common cause of hair loss in men?
androgenic alopecia
anagen phase = 2-6 years (80-90% of hairs on scalp_
What is the treatment for androgenic alopecia?
Minoxidil (Rogaine)
Finasteride (lowers scalp DHT - inhibits 5alpha reductase)
Exclamation point hairs
alopecia areata
T cell mediated inflammation disrupts hair cycle
non-scarring hair loss
onset < 30yo
What is the treatment for alopecia areata?
intralesional triamcinolone
Telogen effluvium
diffuse hair loss
possibly secondary to zinc deficiency or drug use?
positive hair pull sign - follicles are easily extracted
What is impetigo?
superficial bacterial infection of the epidermis
MC s. aureus and Group A strep
Who gets impetigo?
< 6yo MC
How does impetigo present?
honey colored crusts MC on face and extremities
Bullous impetigo vs ecthyma?
bullous impetigo: toxins from S. Aureus - MC on trunk and in folds, less common on face
Ecthyma: deeper into dermis - MC on distal extremities
What is the treatment for impetigo?
Mupirocin (bactroban) - covers MRSA - topical
systemic: cephalexin (keflex)
What is the first line treatment for verrucae?
common warts
salicylic acid
Target or IRIS lesions
erythema multiforme
MC etiology: HSV
Who gets erythema multiforme?
M > F
20-40yo
How does erythema multiforme present?
typically an acute, self limited reaction (1-3 weeks)
prodrome: fever, malaise, myalgia, sore throat, cough
Rash: evolve over days - sharply demarcated
target and IRIS lesions - 3 concentric zones
distal extremities –> usually spread proximally to palms, soles, elbows, and knees
may demonstrate koebner phenomenon
What is the difference b/w erythema multiforme minor and major?
Minor: little or no mucosal involvement
Major: ALWAYS has mucosal involvement - bullous lesions +/- Nikolsky sign
What is the treatment for erythema multiforme?
usually resolves spontaneously within 3-5 weeks
oral antihistamines and topical steroids for sx relief
oral prednisone for severe cases
What causes lichen planus?
mucocutaneous dermatosis
associated with Hep C
How does lichen planus present?
papulosquamous exanthem
6Ps: purple, polygonal, prurutic, planar, papules, plaques
Wickham striae - orally
+/- koebner’s phenomenon
Who gets lichen planus?
1% of the population
30-60yo
majority spontaneously remit in 1-2 years
Oral lichen planus is associated with what?
SCC
What is the treatment for lichen planus?
Topical corticosteroids - clobetasol, betamethasone, deproprionate
intralesional injections of triamcinolone for resistance lesions
What is pityriasis rosea?
etiology is unknown
possibly viral
age of onset: adolescents through adults
spring or fall MC
How does pityriasis rosea present?
Prodrome phase: malaise, HA, mild constitutional sxs
Herald patch: Trunk is MC location
Exanthem - christmas tree distribution
Pediculosis
lice
pediculosis capitis (head lice) pediculosis pubic (pubic lice) pediculosis corpora (body lice) -- can transmit trench fever and typhus
What is the treatment for head lice?
1% permethrin (NIX) and repeat in 1 week
What is the treatment for pubic lice?
1% lindane shampoo for 5 minutes
ALL sexual partners should be treated
FULL sexual workup must be done
Sarcoptes saciei
mite causes scabies
What do you tell a family that is being treated for scabies in regards to expected recovery?
itching may persist for 7-14 days after successful treatment
What is the treatment for scabies?
12 hour application of permethrin 5% location
How can you dx scabies?
apply topical tetraycline and examine skin with wood’s lamp
What is molluscum contagiosum?
a poxvirus (wart like - umbilicated)
Who gets molluscum contagiosum?
rare under 1 yo
MC < 5yo or young adults
How does molluscum contagiosum present?
umbilicated papules 2-5mm skin colored
self limited - takes about 2 months for a single lesion to heal
Urticaria is what type of reaction?
IgE mediated
A pt with urticaria also has arthritis and a fever, what should you be concerned for?
serum sickness
What is the difference between 1st, 2nd, and 3rd degree burns?
1st: epidermis
2nd: dermis
3rd: hypodermis (subcutanous tissue)
Rule of 9s
BSA burns adults: head 9% trunk: 36% arms: 18% legs: 36% perinum: 1%
Parkland formula
LR (fluid of choice)
4ml x BSA burn x weight (kg) = total fluid amount
replace 1/2 in first 8 hours
replace 2nd 1/2 in next 16 hours
Mongolian Spots
dermal melanosis
benign persistence of dermal melanocytes in neonates
blue color is caused by melanocytes
More common in non-caucasian races
MC locations: sacrum and shoulders
gradually fades during first 2 months of life
What is the course of mongolian spots?
gradually fades during first 2 months of life
