Dermatology Flashcards
- 30-40 yoa
- AI disease of unclear etiology
- Abs produced against Ags in intercellular spaces of epidermal cells
- possible causes are idiopathic, ACEI, penicillamine
- bullae are relatively thin and fragile
- POSITIVE Nikolsky’s sign
- PAINFUL
- not pruritic
- fluid loss and risk of infection d/t loss of skin integrity
- life-threatening
- mouth involvement
pemphigus vulgaris
MOST ACCURATE test for pemphigus vulgaris
skin biopsy
treatment for pemphigus vulgaris
steroids
treatment for pemphigus vulgaris if steroids are ineffective
- azathioprine
- mycophenolate
- cyclophosphamide
- 70-80 yoa
- can be sulfa drug-induced
- deep blisters
- thicker bullae much less likely to rupture
- oral lesions are RARE
bullous pemphigoid
test for bullous pemphigoid
skin biopsy w/ immunofluorescent Abs
treatment for bullous pemphigoid
steroids
alternative treatment to steroids for bullous pemphigoid
- tetracycline
- erythromycin w/ nicotinamide
- associated w/ other AI diseases
- can be drug-induced by ACEIs or NSAIDs
- very superficial
- NO oral lesions
pemphigus foliaceus
diagnosis for pemphigus foliaceus
skin biopsy
treatment for pemphigus foliaceus
steroids
- d/o of porphyrin metabolism
- photosensitivity reaction to abnormally high accumulation of porphyrins
- NONHEALING blisters on sun-exposed parts of body
- hyperpigmentation of skin
- hypertrichosis of face
porphyria cutanea tarda
are associated w/ porphyria cutanea tarda
- alcoholism
- liver disease
- chronic hepatitis C
- OCPs
- hemochromatosis
- DM
test for porphyria cutanea tarda
urinary uroporphyrins
treatment for porphyria cutanea tarda
- stop drinking alcohol
- stop all estrogen use
- barrier sun protection
- phlebotomy/deferoxamine
- chloroquine (increases porphyrin excretion)
- hypersensitivity reaction, most often mediated by IgE and mast cell activation
- evanescent wheals and hives (onset w/i 30 minutes, and lasts
urticaria
MCC of urticaria
- medications
- insect bites
- foods
- emotions
- latex
chronic urticaria is associated w/
- pressure on skin
- cold
- vibration
treatment for severe, acute urticaria
- H1 antihistamines
- steroids if life-threatening
treatment for chronic urticaria
H2 antihistamines
treatment for urticaria when trigger cannot be avoided
desensitization
- milder version of hypersensitivity reaction than urticaria
- “typical” drug reaction
- rash resembles MEASLES (hence the name)
- can appear days after exposure, and even after medication has been stopped
- lymphocyte mediated
morbilliform rash
treatment for morbilliform rash
antihistamines
erythema multiforme causes
- penicillins
- phenytoin
- NSAIDs
- sulfa drugs
- HSV, or mycoplasma infection
- target-like lesions especially on PALMS and SOLES
- can be described as “iris-like”
erythema multiforme
treatment for erythema multiforme
antihistamines and treat underlying infection
- hypersensitivity response to medications (penicillins, sulfa drugs, NSAIDs, phenytoin, phenobarbital)
- involves
Stevens-Johnson syndrome (SJS)
treatment for Stevens-Johnson syndrome (SJS)
- should be managed in burn unit
- IVIG, cyclophosphamide, cyclosporine, or thalidomide
- most serious version of cutaneous hypersensitivity reaction
- 30-100% BSA involvement
- positive Nikolsky’s sign
- drug-induced
toxic epidermal necrolysis
MCC of death in toxic epidermal necrolysis
sepsis
are prophylactic systemic antibiotics indicated in toxic epidermal necrolysis?
NO
causes of death in Stevens-Johnson syndrome (SJS)
infection, dehydration, and malnutrition
diagnosis of toxic epidermal necrolysis
skin biopsy
what effect do steroids have in toxic epidermal necrolysis?
decrease chances of survival
- LOCALIZED allergic drug reaction w/ repeated drug exposure
- round, sharply demarcated lesions that leave a hyperpigmented spot at the site after they resolve
fixed drug reaction
treatment for fixed drug reaction
topical steroids
- painful, red, raised nodules on anterior surface of LE’s
- nodules are TTP
- do not ulcerate
- ast about 6 weeks
- 2/2 recent infections or inflammatory conditions
erythema nodosum
inflammatory conditions associated w/ erythema nodosum
- pregnancy
- recent Streptococcal infection
- coccidioidomycosis
- histoplasmosis
- sarcoidosis
- IBD
- syphilis
- hepatitis
- enteric infections
treatment for erythema nodosum
- analgesics and NSAIDs
- treat underlying cause
best INITIAL test for:
- tinea pedis
- tinea cruris
- tinea corporis
- tinea versicolor
- tinea capitis
- onychomycosis
KOH test of skin
MOST ACCURATE test for:
- tinea pedis
- tinea cruris
- tinea corporis
- tinea versicolor
- tinea capitis
- onychomycosis
fungal culture
- superficial bacterial infection
- described as “weeping,” “oozing,” “honey-colored,” or “draining”
- occurs in warm, humid conditions
- more often caused by Staphylococcus, but sometimes Streptococcus pyogenes
impetigo
complication of impetigo
glomerulonephritis
treatment for impetigo
- topical mupirocin
- PO antistaphylococcal abx if topical isn’t enough (dicloxacillin, cephalexin, or cefadroxil (PO))
- involves both dermis and epidermis
- MCC by group A Streptococcus (pyogenes)
- fever, chills, bacteremia
- bright red, angry, swollen appearance to face
erysipelas
treatment for erysipelas
- dicloxacillin, cephalexin, or cefadroxil (PO)
- oxacillin, nafcillin, cefazolin (IV)
if a pt is allergic to PCN w/ reaction being a RASH ONLY, can cephalosporins be used?
YES
if a pt is allergic to PCN w/ reaction being ANAPHYLAXIS, can cephalosporins be used?
NO
treatment for erysipelas if culture confirms Streptococcus
PCN G, or ampicillin (IV)
- involves dermis, and subcutaneous tissue
- caused by Staphylococcus, or Streptococcus
- +/- fever, hypotension, signs of sepsis
cellulitis
empiric treatment for cellulitis
oxacillin, nafcillin, cefazolin (IV)
treatment for mild cellulitis w/ MRSA
TMP/SMX, doxycycline, or clindamycin
- extremely severe, life-threatening skin infection
- starts as cellulitis that dissects into fascial planes
- Streptococcus and Clostridium are MC organisms
- increased risk with DM pts
necrotizing fasciitis
necrotizing fasciitis presentation:
- very high fever
- portal of entry into skin
- pain out of proportion to superficial appearance
- bullae
- palpable crepitus
diagnostic tests for necrotizing fasciitis
- CPK
- XR, CT, or MRI to show air in tissue, or necrosis
best way to confirm diagnosis and mainstay treatment for necrotizing fasciitis
surgical debridement
antibiotic treatment for necrotizing fasciitis
- ampicillin/sulbactam
- ticarcillin/clavulanate
- piperacillin/tazobactam
treatment for necrotizing fasciitis if there is definite diagnosis of group A Streptococcus (pyogenes)
clindamycin and PCN
mortality rate of necrotizing fasciitis w/o adequate treatment
80%
infection loculated under skin surrounding a nail
paronychia
treatment for paronychia
- small incision to drain
- antistaphylococcal abx
(dicloxacillin, cephalexin, or cefadroxil (PO))
multiple, painful vesicles of genitals
herpes simplex
best INITIAL test for genital herpes simplex
Tzanck smear
MOST ACCURATE test for genital herpes simplex
viral culture
treatment for genital herpes simplex
PO acyclovir, famciclovir, or valacyclovir
when should you treat a child for chickenpox?
if immunocompromised
same meds: PO acyclovir, famciclovir, or valacyclovir
complications of varicella
- PNA
- hepatitis
- dissemination
treatment for severe pain in elderly pts w/ dermatomal herpes zoster
steroids
best efficacy for decreasing risk of postherpetic neuralgia in dermatomal herpes zoster
acyclovir
nonimmune adults exposed to chickenpox should receive what?
varicella zoster immune globulin w/i 96 hours of exposure
- warts (condylomata acuminata) [heaped up, translucent, white or flesh-colored lesions on mucous surfaces]
human papillomavirus (HPV)
treatment for human papillomavirus (HPV)
- mechanical removal
- imiquimod
- ulceration w/ heaped-up indurated edges
- painLESS
primary syphilis
best INITIAL test for primary syphilis
darkfield microscopy
treatment for primary syphilis
IM PCN single dose
treatment for primary syphilis if PCN allergic
PO doxycycline x 2 weeks
- generalized copper-colored, maculopapular rash especially on PALMS and SOLES
- mucous patch
- alopecia areata
- condylomata lata
secondary syphilis
diagnostic tests for secondary syphilis
VDRL, or RPR (nearly 100% sensitive)
treatment for secondary syphilis
IM PCN single dose
treatment for secondary syphilis if PCN allergic
PO doxycycline x 2 weeks
- skin infection involving web spaces of hands and feet
- can also cause pruritic lesions around penis and breast
- burrows and excoriations around small pruritic vesicles
- often spares the head
scabies
scabies is confirmed by
scraping out organism after mineral oil is applied to burrow
best INITIAL treatment for scabies
permethrin
treatment for Norwegian scabies (severe crusting)
PO ivermectin
- includes the head
- easily transmitted
- extremely high rate of transmission
- sometimes rust colored from ingestion of blood
pediculosis (lice and crabs)
diagnosis of pediculosis (lice and crabs)
can be seen attached to hair-bearing areas
treatment for pediculosis (lice and crabs)
permethrin
- target lesion (> 85%) = rash must be erythematous w/ central clearing and be at least 5cm in diameter
- usually occurs 7-10 days after tick bite
lyme disease
treatment for lyme disease
doxycycline, amoxicillin, or cefuroxime (PO)
- caused by Staphylococcus attached to a foreign body (nasal packing, retained sutures, surgical material retained in the body)
- fever > 102
- SBP
toxic shock syndrome (TSS)
treatment for toxic shock syndrome (TSS)
- vigorous fluid resuscitation
- vasopressors
- antistaphylococcal abx
(oxacillin, nafcillin, cefazolin (IV))
treatment for toxic shock syndrome (TSS) if MRSA
vancomycin, or linezolid
- mediated by toxin from Staphylococcus
- loss of superficial layers of epidermis
- Nikolsky’s sign
- presents w/ NORMAL BP
- NO involvement of liver, kidney, BM, or CNS
Staphylococcal scalded skin syndrome (SSSS)
treatment for Staphylococcal scalded skin syndrome (SSSS)
IV oxacillin, or nafcillin
- cutaneous infection acquired from contact w/ infected livestock
- occupational hazard of wool sorters
- can be used for bioterrorism
- papule w/ central necrosis (eschar)
- 20% fatality if untreated
anthrax
Bacillus anthracis
how is the diagnosis of anthrax confirmed?
gram stain and culutre
treatment for anthrax
ciprofloxacin, or doxycycline
MOST ACCURATE test for melanoma
full thickness biopsy of lesion
most important prognostic factor for melanoma
tumor thickness
treatment for melanoma
excision
reduces recurrence rates of melanoma
interferon
- BENIGN
- hyperpigmented lesions in elderly pts (“stuck on” appearance)
seborrheic keratosis
- PRECANCEROUS (increases risk of SCC)
- occur on sun-exposed areas in older pts
- can be TTP
actinic keratosis
treatment for actinic keratosis
- cryotherapy
- topical 5-FU
- imiquimod
- topical retinoic acid
- curettage
- sun-exposed areas in elderly pts
- commonly on the lip
- ULCERATION is common
- metastasis is rare
squamous cell carcinoma
diagnosis of squamous cell carcinoma
biopsy
treatment for squamous cell carcinoma
surgical removal
- shiny, or “pearly” appearance
- accounts for 65-80% of skin cancer
basal cell carcinoma
how is diagnosis of basal cell carcinoma confirmed?
shave or punch biopsy
treatment for basal cell carcinoma
surgical removal (Mohs microsurgery)
- purplish lesions
- HIV-positive w/ CD4 count
kaposi’s sarcoma
treatment for kaposi’s sarcoma
- ART to raise CD4 count
- liposomal doxorubicin and vinblastine if HIV-negative
- silvery scales on EXTENSOR surfaces
- nail pitting
- Koebner phenomenon (lesions that develop at site of epidermal injury)
psoriasis
treatment for psoriasis
- emollients (moisturizer)
- salicylic acid
treatment for xerosis/asteatotic dermatitis
humidifiers and emollients
- high IgE levels
- red, itchy plaques on FLEXOR surfaces
atopic dermatitis
preventive treatment for atopic dermatitis
emollients
treatment for active disease of atopic dermatitis
- AVOID SCRATCHING
- topical steroids
- antihistamines
- oversecretion of sebaceous material
- hypersensitivity reaction to superficial fungal organism (Pityrosporum ovale)
- scaly, greasy, flaky skin found on red base of scalp, eyebrows, and nasolabial fold
seborrheic dermatitis
treatment for seborrheic dermatitis
- topical steroids
- topical antifungal
- zinc pyrithione
- hyperpigmentation built up from hemosiderin
- occurs over long period from VENOUS incompetence of LE’s
stasis dermatitis
prevention of stasis dermatitis
elevation of LE’s
- hypersensitivity reaction to soaps, detergents, latex, sunscreen, or neomycin
- jewelry is a common cause
- can present as linear streaked vesicles (especially when caused by poison ivy)
contact dermatitis
definitive testing for contact dermatitis
patch testing
treatment for contact dermatitis
- identifying causative agent
- antihistamines and topical steroids
- pruritic eruption that begins w/ “herald patch”
- erythematous and salmon colored
- mild and self-limited, resolves in 8 weeks
pityriasis rosea
- pustules and cysts occur and rupture
- caused by Propionibacterium acnes
- discharge is odorless
acne
treatment for acne: mild disease
- topical antibiotics: clindamycin, erythromycin, or sulfacetamide
- topical retinoids
treatment for acne: moderate disease
benzoyl peroxide and retinoids
treatment for acne: severe cystic acne
- PO antibiotics
- PO retinoic acid derivatives
definition of stage 1 pressure ulcer
nonblanchable erythema of INTACT skin
definition of stage 2 pressure ulcer
superficial ulcers causing PARTIAL thickness loss of epidermis, dermis, or both
definition of stage 3 pressure ulcer
deeper ulcers causing FULL thickness loss w/ damage to subcutaneous tissue that may extend to, but NOT through, any underlying fascia
definition of stage 4 pressure ulcer
VERY deep ulcers causing FULL thickness loss w/ EXTENSIVE tissue destruction that may damage adjacent muscle, bone, or supporting structures