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Flashcards in Dermatology Deck (104)
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1

flat spot less than 1cm (non-palpable, just visible)
ex:freckles, tattoos

macule

2

flat spot>1cm
ex:port wine stain

patch

3

solid, elevated lesion

papule

4

same as papule but >!cm and flat-topped
ex: psoriasis

plaque

5

palpable, solid lesion >1cm, not flat-topped
ex: small lipoma
erythema nodosum

nodule

6

elevated circumscribed lesion

vesicle

7

same as vesicle but >5mm (large blister)
ex. contact dermatitis, pemphigus

bulla

8

Itchy, transiently edematous area
ex:allergic reaction

wheal

9

erysipelas

upper dermis
superficial lymphatics

may appear raised with clear line of demarcation

10

cellulitis

deeper dermis
subcutaneous fat

11

risk factors for erysipelas and cellulitis

chronic skin problems
diabetes mellitus
chronic swelling of LE
IV drug use
immunocompromiased state
penetration of skin (surgery/trauma)
previous cellulitis

12

Diagnosis and labs in cellulitis and erysipelas

Clinical diagnosis
increased WBC count, ESR, CRP
blood cx

13

Common organisms in cellulitis

1. beta- hemolytic strep
s. pyogenes, group B strep

2. s. aureus common in abscesses

14

How do we treat cellulitis

non-purulent cellulitis:
PO- dicloxacillin
cephalexin
clindamycin

IV- cefazolin
nafcillin
clindamycin

purulent cellulitis:
PO- clindamycin
TMP-SMX
Doxycycline
Linezolid

IV abx-
vancomycin

15

Skin abscesses

collection of pus within dermis and deeper skin tissues

16

Furuncle (boil):

infection of hair follicle
purulent material extends through dermis into subQ tissue

often drains spontaneously

17

Carbuncle

coalescence of several inflamed follicles

18

Diagnosis of abcess, furuncle, carbuncle

clinical

culture is indicated for bacterial idenfication
-s.aureus in 75% of cases

19

Treatment of skin abscess

let the pus out

if large,
incision and drainage
for patients at risk of endocarditis: vancomycin 1hr prior to incision and drainage

oral: clindamycin, tmp-smx, doxycycline, linezolid

IV: vancomycin

antibiotics are often unsuccessful because you need to get the pus out

20

Hidradenitis suppurative

recurrent infection/occlusion of apocrine glands

MC site: axilla

Tx:
-general measures: avoid skin trauma, gentle cleansing, smoking cessation, weight loss

-mild disease: topical clindamycin daily, punch debridement

second line: clindamycin with rifampin

severe disease: oral doxycycline or minocycline, more invasive surgical debridement
-alternative treatments: intralesional steroids, anti-adrenergic drugs, TNFa inhibitors, oral retinoids

21

necrotizing fasciitis

infection spreading along fascial plane

polymicrobial- anaerobes, gram +, gram -
GAS
often in the setting of some systemic disease

H and P:
unexplained, excrutiating pain in the absence of or beyond areas of cellulitis

bulla, necrosis, crepitus

Dx: surgical exploration is the only way to definitively diagnose, as well as to treat

rapidly worsening cellulitis with severe pain

Xray: crepitus, subcutaneous air can be seen with plain film on an xray

22

Fournier gangrene

perineal cellulitis with abrupt onset and rapid spread

this is a urological emergency

23

What is the general treatment for necrotizing fasciitis?

immediate aggressive surgical debridement

abx:
1. carbapenem (imipenem or meropenem)
or beta-lactam plus beta-lactamase inhibitor (piperacillin +tazobactam)
PLUS
2. clindamycin
PLUS
3. vancomycin

24

Gangrene

significant amounts of body tissue necrosis

a chronic condition compared with necrotizing fasciitis

dry gangrene (chronic, distal, severe ischemia) treat with revascularization or allow auto-amputation

wet gangrene: bacterial infection in moist tissue: debridement, possible amputation

gas gangrene: caused by clostridium perfringens
-debridement
-hyperbaric oxygen
-antibiotics

25

Impetigo

contagios skin infection among young children
s. aureus is MCC (MSSA)
s. pyogenes

vesicles that form and rupture to form thick crust, most commonly on the face

Treatment:
mild- mupirocin

moderate-severe: dicloxacillin, cephalexin

MRSA: clindamycin, TMP-SMX, doxycycline

26

Acne vulgaris

1. hyperkeratosis
-retinoic acid (tretinoin)
-isotretinoin is PO, potent
2. sebum overproduction
-isotretinoin
-tretinoin
-spironolactone (anti-androgen, decreases testosterone and cortisol)
-OCP

3. propionibacterium acnes proliferation
-erythromyicin PO
-tertracycline PO
-doxycycline PO
-minocycline PO
-clindamycin PO
-topical clindamycin
-benzoyl peroxide

4. inflammation
-steroids

affecting areas that have hormonally- sensitive sebaceous glands

27

isotretinoin side effects

hepatotoxicity
teratogenic
drying and cracking of skin and lips
depression
elevated TG

28

Acne drugs that can cause photosensitivity

tetracycline
doxycycline
tretinoin

29

Rosacea

cause is not understood
inflammation, UV damage, vascular damage

middle- aged patient
facial erythema with telangiectasias starting at nose and cheeks
recurrent facial flushing provoked by various stimuli including hot/spicy foods, alcohol, temperature extremes, emotional reactions

no comedones, but otherwise looks a little like acne

ocular blepharitis, conjunctivitis, keratitis

bumpy nose (sebaceous gland hyperplasia)- rhinophyma

Topical treatment:
-metronidazole
-azeleic acid

Systemic treatment:
-tetracycline, doxycycline, minocycline
-isotretinoin for severe refractory cases
-laser therapy for rhinophyma

30

HSV

recurrent viral infection of mucocutaneous surfaces

HSV1- oral disease
viral genetic disease in sensory areas

cold sores every month, every 5 years

small painful vesicles around the mouth, lasting several days

eyes, esophagus

Herpetic whitlow- cutical, painful

Dx:
Tzanck smear on a q-tip
viral culture
serology

Tx: treats symptoms, can't be cured
acyclovir
famciclovir
valacyclovir

contagious even when you don't see lesions

Vertical transmission can cause disseminated disease

Newborns can get herpes temporal lobe encephalitis