Dermatology Flashcards Preview

USMLE Step 3 > Dermatology > Flashcards

Flashcards in Dermatology Deck (134):
1

- 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

2

MOST ACCURATE test for pemphigus vulgaris

skin biopsy

3

treatment for pemphigus vulgaris

steroids

4

treatment for pemphigus vulgaris if steroids are ineffective

- azathioprine
- mycophenolate
- cyclophosphamide

5

- 70-80 yoa
- can be sulfa drug-induced
- deep blisters
- thicker bullae much less likely to rupture
- oral lesions are RARE

bullous pemphigoid

6

test for bullous pemphigoid

skin biopsy w/ immunofluorescent Abs

7

treatment for bullous pemphigoid

steroids

8

alternative treatment to steroids for bullous pemphigoid

- tetracycline
- erythromycin w/ nicotinamide

9

- associated w/ other AI diseases
- can be drug-induced by ACEIs or NSAIDs
- very superficial
- NO oral lesions

pemphigus foliaceus

10

diagnosis for pemphigus foliaceus

skin biopsy

11

treatment for pemphigus foliaceus

steroids

12

- 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

13

are associated w/ porphyria cutanea tarda

- alcoholism
- liver disease
- chronic hepatitis C
- OCPs
- hemochromatosis
- DM

14

test for porphyria cutanea tarda

urinary uroporphyrins

15

treatment for porphyria cutanea tarda

- stop drinking alcohol
- stop all estrogen use
- barrier sun protection
- phlebotomy/deferoxamine
- chloroquine (increases porphyrin excretion)

16

- hypersensitivity reaction, most often mediated by IgE and mast cell activation
- evanescent wheals and hives (onset w/i 30 minutes, and lasts

urticaria

17

MCC of urticaria

- medications
- insect bites
- foods
- emotions
- latex

18

chronic urticaria is associated w/

- pressure on skin
- cold
- vibration

19

treatment for severe, acute urticaria

- H1 antihistamines
- steroids if life-threatening

20

treatment for chronic urticaria

H2 antihistamines

21

treatment for urticaria when trigger cannot be avoided

desensitization

22

- 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

23

treatment for morbilliform rash

antihistamines

24

erythema multiforme causes

- penicillins
- phenytoin
- NSAIDs
- sulfa drugs
- HSV, or mycoplasma infection

25

- target-like lesions especially on PALMS and SOLES
- can be described as "iris-like"

erythema multiforme

26

treatment for erythema multiforme

antihistamines and treat underlying infection

27

- hypersensitivity response to medications (penicillins, sulfa drugs, NSAIDs, phenytoin, phenobarbital)
- involves

Stevens-Johnson syndrome (SJS)

28

treatment for Stevens-Johnson syndrome (SJS)

- should be managed in burn unit
- IVIG, cyclophosphamide, cyclosporine, or thalidomide

29

- most serious version of cutaneous hypersensitivity reaction
- 30-100% BSA involvement
- positive Nikolsky's sign
- drug-induced

toxic epidermal necrolysis

30

MCC of death in toxic epidermal necrolysis

sepsis

31

are prophylactic systemic antibiotics indicated in toxic epidermal necrolysis?

NO

32

causes of death in Stevens-Johnson syndrome (SJS)

infection, dehydration, and malnutrition

33

diagnosis of toxic epidermal necrolysis

skin biopsy

34

what effect do steroids have in toxic epidermal necrolysis?

decrease chances of survival

35

- 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

36

treatment for fixed drug reaction

topical steroids

37

- 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

38

inflammatory conditions associated w/ erythema nodosum

- pregnancy
- recent Streptococcal infection
- coccidioidomycosis
- histoplasmosis
- sarcoidosis
- IBD
- syphilis
- hepatitis
- enteric infections

39

treatment for erythema nodosum

- analgesics and NSAIDs
- treat underlying cause

40

best INITIAL test for:

- tinea pedis
- tinea cruris
- tinea corporis
- tinea versicolor
- tinea capitis
- onychomycosis

KOH test of skin

41

MOST ACCURATE test for:

- tinea pedis
- tinea cruris
- tinea corporis
- tinea versicolor
- tinea capitis
- onychomycosis

fungal culture

42

- 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

43

complication of impetigo

glomerulonephritis

44

treatment for impetigo

- topical mupirocin
- PO antistaphylococcal abx if topical isn't enough (dicloxacillin, cephalexin, or cefadroxil (PO))

45

- involves both dermis and epidermis
- MCC by group A Streptococcus (pyogenes)
- fever, chills, bacteremia
- bright red, angry, swollen appearance to face

erysipelas

46

treatment for erysipelas

- dicloxacillin, cephalexin, or cefadroxil (PO)
- oxacillin, nafcillin, cefazolin (IV)

47

if a pt is allergic to PCN w/ reaction being a RASH ONLY, can cephalosporins be used?

YES

48

if a pt is allergic to PCN w/ reaction being ANAPHYLAXIS, can cephalosporins be used?

NO

49

treatment for erysipelas if culture confirms Streptococcus

PCN G, or ampicillin (IV)

50

- involves dermis, and subcutaneous tissue
- caused by Staphylococcus, or Streptococcus
- +/- fever, hypotension, signs of sepsis

cellulitis

51

empiric treatment for cellulitis

oxacillin, nafcillin, cefazolin (IV)

52

treatment for mild cellulitis w/ MRSA

TMP/SMX, doxycycline, or clindamycin

53

- 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

54

necrotizing fasciitis presentation:

- very high fever
- portal of entry into skin
- pain out of proportion to superficial appearance
- bullae
- palpable crepitus

55

diagnostic tests for necrotizing fasciitis

- CPK
- XR, CT, or MRI to show air in tissue, or necrosis

56

best way to confirm diagnosis and mainstay treatment for necrotizing fasciitis

surgical debridement

57

antibiotic treatment for necrotizing fasciitis

- ampicillin/sulbactam
- ticarcillin/clavulanate
- piperacillin/tazobactam

58

treatment for necrotizing fasciitis if there is definite diagnosis of group A Streptococcus (pyogenes)

clindamycin and PCN

59

mortality rate of necrotizing fasciitis w/o adequate treatment

80%

60

infection loculated under skin surrounding a nail

paronychia

61

treatment for paronychia

- small incision to drain
- antistaphylococcal abx
(dicloxacillin, cephalexin, or cefadroxil (PO))

62

multiple, painful vesicles of genitals

herpes simplex

63

best INITIAL test for genital herpes simplex

Tzanck smear

64

MOST ACCURATE test for genital herpes simplex

viral culture

65

treatment for genital herpes simplex

PO acyclovir, famciclovir, or valacyclovir

66

when should you treat a child for chickenpox?

if immunocompromised

(same meds: PO acyclovir, famciclovir, or valacyclovir)

67

complications of varicella

- PNA
- hepatitis
- dissemination

68

treatment for severe pain in elderly pts w/ dermatomal herpes zoster

steroids

69

best efficacy for decreasing risk of postherpetic neuralgia in dermatomal herpes zoster

acyclovir

70

nonimmune adults exposed to chickenpox should receive what?

varicella zoster immune globulin w/i 96 hours of exposure

71

- warts (condylomata acuminata) [heaped up, translucent, white or flesh-colored lesions on mucous surfaces]

human papillomavirus (HPV)

72

treatment for human papillomavirus (HPV)

- mechanical removal
- imiquimod

73

- ulceration w/ heaped-up indurated edges
- painLESS

primary syphilis

74

best INITIAL test for primary syphilis

darkfield microscopy

75

treatment for primary syphilis

IM PCN single dose

76

treatment for primary syphilis if PCN allergic

PO doxycycline x 2 weeks

77

- generalized copper-colored, maculopapular rash especially on PALMS and SOLES
- mucous patch
- alopecia areata
- condylomata lata

secondary syphilis

78

diagnostic tests for secondary syphilis

VDRL, or RPR (nearly 100% sensitive)

79

treatment for secondary syphilis

IM PCN single dose

80

treatment for secondary syphilis if PCN allergic

PO doxycycline x 2 weeks

81

- 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

82

scabies is confirmed by

scraping out organism after mineral oil is applied to burrow

83

best INITIAL treatment for scabies

permethrin

84

treatment for Norwegian scabies (severe crusting)

PO ivermectin

85

- includes the head
- easily transmitted
- extremely high rate of transmission
- sometimes rust colored from ingestion of blood

pediculosis (lice and crabs)

86

diagnosis of pediculosis (lice and crabs)

can be seen attached to hair-bearing areas

87

treatment for pediculosis (lice and crabs)

permethrin

88

- 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

89

treatment for lyme disease

doxycycline, amoxicillin, or cefuroxime (PO)

90

- 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)

91

treatment for toxic shock syndrome (TSS)

- vigorous fluid resuscitation
- vasopressors
- antistaphylococcal abx
(oxacillin, nafcillin, cefazolin (IV))

92

treatment for toxic shock syndrome (TSS) if MRSA

vancomycin, or linezolid

93

- 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)

94

treatment for Staphylococcal scalded skin syndrome (SSSS)

IV oxacillin, or nafcillin

95

- 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)

96

how is the diagnosis of anthrax confirmed?

gram stain and culutre

97

treatment for anthrax

ciprofloxacin, or doxycycline

98

MOST ACCURATE test for melanoma

full thickness biopsy of lesion

99

most important prognostic factor for melanoma

tumor thickness

100

treatment for melanoma

excision

101

reduces recurrence rates of melanoma

interferon

102

- BENIGN
- hyperpigmented lesions in elderly pts ("stuck on" appearance)

seborrheic keratosis

103

- PRECANCEROUS (increases risk of SCC)
- occur on sun-exposed areas in older pts
- can be TTP

actinic keratosis

104

treatment for actinic keratosis

- cryotherapy
- topical 5-FU
- imiquimod
- topical retinoic acid
- curettage

105

- sun-exposed areas in elderly pts
- commonly on the lip
- ULCERATION is common
- metastasis is rare

squamous cell carcinoma

106

diagnosis of squamous cell carcinoma

biopsy

107

treatment for squamous cell carcinoma

surgical removal

108

- shiny, or "pearly" appearance
- accounts for 65-80% of skin cancer

basal cell carcinoma

109

how is diagnosis of basal cell carcinoma confirmed?

shave or punch biopsy

110

treatment for basal cell carcinoma

surgical removal (Mohs microsurgery)

111

- purplish lesions
- HIV-positive w/ CD4 count

kaposi's sarcoma

112

treatment for kaposi's sarcoma

- ART to raise CD4 count
- liposomal doxorubicin and vinblastine if HIV-negative

113

- silvery scales on EXTENSOR surfaces
- nail pitting
- Koebner phenomenon (lesions that develop at site of epidermal injury)

psoriasis

114

treatment for psoriasis

- emollients (moisturizer)
- salicylic acid

115

treatment for xerosis/asteatotic dermatitis

humidifiers and emollients

116

- high IgE levels
- red, itchy plaques on FLEXOR surfaces

atopic dermatitis

117

preventive treatment for atopic dermatitis

emollients

118

treatment for active disease of atopic dermatitis

- AVOID SCRATCHING
- topical steroids
- antihistamines

119

- 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

120

treatment for seborrheic dermatitis

- topical steroids
- topical antifungal
- zinc pyrithione

121

- hyperpigmentation built up from hemosiderin
- occurs over long period from VENOUS incompetence of LE's

stasis dermatitis

122

prevention of stasis dermatitis

elevation of LE's

123

- 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

124

definitive testing for contact dermatitis

patch testing

125

treatment for contact dermatitis

- identifying causative agent
- antihistamines and topical steroids

126

- pruritic eruption that begins w/ "herald patch"
- erythematous and salmon colored
- mild and self-limited, resolves in 8 weeks

pityriasis rosea

127

- pustules and cysts occur and rupture
- caused by Propionibacterium acnes
- discharge is odorless

acne

128

treatment for acne: mild disease

- topical antibiotics: clindamycin, erythromycin, or sulfacetamide
- topical retinoids

129

treatment for acne: moderate disease

benzoyl peroxide and retinoids

130

treatment for acne: severe cystic acne

- PO antibiotics
- PO retinoic acid derivatives

131

definition of stage 1 pressure ulcer

nonblanchable erythema of INTACT skin

132

definition of stage 2 pressure ulcer

superficial ulcers causing PARTIAL thickness loss of epidermis, dermis, or both

133

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

134

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