MTB - Dermatology Flashcards
ab’s to intercellular space of epidermal cells
pemphigus vulgaris
causes of pemphigus vulgaris:
idiopathic
ACE inhibitors
Penicillamine
3 diseases that have positive Nikolsky’s sign
pemphigus vulgaris
TEN
SSSS
are the lesions in pemphigus painful or pruritic?
painful
most accurate dx test - pemphigus vulgaris
biopsy of the skin
DOC: pemphigus vulgaris
glucocorticoids - prednisone
what drugs can be used in pemphigus if steroids are ineffective?
azathioprine
mycophenolate
cyclophosphamide
dz characterized by tense bullae formation, usually in an elderly person
bullous pemphigoid
Dx. test - bullous pemphigoid
biopsy w/ immunofluorescent abs
Tx. bullous pemphigoid
systemic steroids (prednisone)
alternatives:
- tetracycline
-erythromycin w/ nicotinamide
Pemphigus Foliaceus
blistering dz assoc with other autoimmune diseases or drugs (ACE inhibitors or NSAIDs); much more superficial than pemphigus
a patient presents with nonhealing blisters on sun-exposed parts of the body, hyperpigmentation of the skin and hypertrichosis of the face - dx?
porphyria cutanea tarda
- abnormal photosensitivity reaction
porphyria cutanea tarda is associated with…
alcoholism liver disease hep C OCP use liver dz - chronic hepatitis, hemochromatosis diabetes
Dx test - porphyria cutanea tarda
urinary uroporphyrins
Tx. porphyria cutanea tarda
- stop drinking alcohol
- stop estrogen use
- use barrier sun protection
- use phlebotomy or deferoxamine
- chloroquine (increases excretion of porphyrins)
uriticaria
hypersensitivity reaction mediated by IgE and mast cell activation resulting in wheals and hives and pruritus.
Medications causing uriticaria
aspirin NSAIDs morphine/codeine penicillins phenytoin quinolones
MCC of uriticaria
medications insect bites foods emotions contact w/ latex
Management - uriticaria
severe and acute? first generation anti-histamines
chronic? newer gen, nonsedating anti-histamines
morbilliform rash
typical type of drug reaction - generalized maculopapular eruption that blanches with pressure; mediated by lymphocytes
tx. morbilliform rash
antihistamines
causes of erythema multiforme
penicillins phenytoin NSAIDs sulfa drugs infection w/ herpes simplex or mycoplasma
describe erythema multiforme
targetlike lesions esp. on palms and soles; does not involve mucosal membranes
Tx. erythema multiforme
antihistamines
Stevens-Johnson syndrome
Hypersensitivity reaction involving < 10-15% of BSA and mucous membrane involvement (oral cavity and conjunctivae)
What meds can cause SJS?
penicillins sulfa drugs NSAIDs phenytoin phenobarbital
Management of SJS
pts should be managed in burn unit (high risk for infection, dehydration and malnutrition)
meds to try: IVIG, cyclophosphamide, cyclosporine, thalidomide
Toxic Epidermal Necrolysis
most serious version of cutaneous hypersensitivity
- involves from 30-100% of BSA w/ mortality of 40-50% (MCC of death is due to sepsis)
Dx. TEN
skin biopsy
fixed drug reaction
localized allergic drug reaction that recurs at precisely the same anatomic site on skin w/ repeated drug exposure leaving a hyperpigmented, sharply demarcated spot
tx. fixed drug reaction
topical steroids
causes of erythema nodosum
pregnancy recent streptococcal infection coccidioidomycosis histoplasmosis sarcoidosis IBD syphillis hepatitis enteric infections - Yersinia
tx. erythema nodosum
analgesics, NSAIDs
best initial test for fungal infection of the skin
KOH prep
most accurate test for fungal skin infection
culture of fungus (take up to 6 weeks)
Tx. onychomycosis or tinea capitis
oral terbinafine or itraconazole
6 weeks - fingernails
12 weeks - toenails
s/e: terbenafine
hepatotoxic –> monitor LFTs periodically
s/e: systemic ketoconazole
hepatotoxicity
gynecomastia
which anti-fungal does NOT come in a topical form
fluconazole
Tx. mild bacterial skin infections
dicloxacillin, cephalexin (Keflex) or Cefadroxil (Duricef)
Tx. moderate-severe bacterial skin infections
IV oxacillin/nafcillin or IV cefazolin
pt with bacterial skin infection, gets a rash with penicillin - what drug can you use?
cephalosporins are OK (Cefadroxil or cefazolin)
pt with bacterial skin infection, anaphylaxis allergy to penicillin - what can you use to treat his infection?
macrolides - erythromycin, azithromycin, clarithromycin
newer FQs
MC organisms causing necrotizing fasciitis
Streptococcus
Clostridia
CF: necrotizing fasciitis
very high fever portal of entry to skin pain out of proportion to superficial appearance bullae palpable crepitus
Dx. necrotizing fasciitis
elevated CPK
Imaging showing air in the tissue/necrosis
best initial step: SURGERY (debridement)
Tx. necrotizing fasciitis
Ampicillin/Sulbactam
Ticarcillin/Clavulanate
Piperacillin/Tazobactam
if strep infection: Clindamycin + Penicillin
what has the best efficacy for decreasing the risk of postherpetic neuralgia from herpes zoster
rapid admin of acyclovir
most effective analgesic for postherpetic neuralagia
gabapentin
Criteria for Toxic Shock Syndrome
fever > 102 systolic BP < 90 desquamative rash vomiting involvement of mucous mbs of eye, mouth and genitals
Lab findings in TSS
elevated Cr, CPK, LFTs
lowers platelets
Tx. TSS
- IVF
- pressors ie DA
- antistaph meds: oxacillin, nafcillin or cefazolin (if MRSA - vancomycin, linezolid)
Staphylococcal Scalded Skin Syndrome
Skin infection mediated by toxin released by staphylococcus causing sloughing off of superficial layers of epidermis (granular layer) in sheets (positive Nikolsky); no other organ involvement like as in TEN
Tx. SSSS
manage in a burn unit
Oxacillin/Nafcillin
Tx. Anthrax
Ciprofloxacin
Doxycycline
Tx. seborrheic dermatitis
liquid nitrogen or curretage
- removal only for cosmetic purposes
Tx. actinic keratosis
cryotherapy, topical 5FU, imiquimod, topical retinoic acid, curettage
chemotherapy for Kaposi’s sarcoma
liposomal Adriamycin and vinblastine
Tx. psoriasis
- emollients
- salicylic acid - removes crust
- topical steroids (if localized)
- topical vitamin D (calcipotriene) and vitamin A (tazarotene) (chronic psoriasis)
if psoriasis covers > 30% of BSA, treatment?
PUVA therapy
severe, widespread and progressive psoriasis - tx?
methotrexate
seborrheic dermatitis
oversecretion of sebaceous material; HS rxn to a superficial fungal organism (pityrosporum ovale)
Tx. seborrheic dermatitis
low potency topical steroids - hydrocortisone
topical antifungals
zinc pyrithione shampoo
stasis dermatitis
hyperpigmentation that is built up hemosiderin in tissue from long periods of venous incompetence of LE (no way to reverse this)
Tx. keloid scars
intralesional corticosteroids
- recurrence after treatment is common
Tx. psoriasis localized to the skin
topical high potency steroids (betamethasone 0.05%)
Tx. psoriasis that involves > 30% of the body surface area
phototherapy with UVB radiation
when is MTX used in psoriasis?
severe psoriasis
psoriatic arthritis
psoriasis involving the nails
drugs that may exacerbate psoriasis lesions
- beta blockers
- antimalarial drugs
- NSAIDs
- ACE inhibitors
- lithium
stage 1 pressure ulcers
nonblanchable erythema of intact skin
stage 2 pressure ulcers
superficial ulcers causing a partial thickness of epidermis, dermis or both
stage 3 pressure ulcers
full thickness loss with damage to subcutaneous tissue that may extend to but not through any underlying fascia
stage 4 pressure ulcers
very deep ulcers causing full thickness loss with extensive destruction that may damage adjacent muscle, bone or supporting structures
tx. stage 3 or 4 pressure ulcers
pack with saline moistened gauze or cover with occlusive dressing
most accurate test for dx of psoriasis
skin biopsy
- epidermal hyperplasia or hyperproliferation with neutrophillic infiltrate into stratum corneum and thinned to absent granular layer of epidermis
initial drug of choice for psoriatic arthritis
Methotrexate
- once weekly low dose regimen
topical treatments for psoriasis
low potency steroids (hydrocort) - face, intertriginous areas, thin plaques
high potency steroids (thick plaques)
anthralin - mild psoriasis
calcipotriene - moderate plaque psoriasis
clinical associations with alopecia areata
- exclamation point hairs, esp at periphery
- nail pitting
- other autoimmune conditions: thyroid dz, vitiligo, pernicious anemia
drugs implicated in telogen efflivum
beta blockers anticoagulants systemic retinoids anticonvulsants antithyroid medications
