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