Musculoskeletal, Skin, and CT - First Aid Flashcards Preview

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Flashcards in Musculoskeletal, Skin, and CT - First Aid Deck (286):
1

Tight junction (aka zonula occludens)

prevents paracellular movement of solutes; composed of claudins and occludins

2

Adherens junction (aka zonula adherens)

below tight junction; forms belt connecting actin cytoskeletons of adjacent cells with cadherins

3

Cadherins are...

Ca2+ dependent adhesion proteins.

4

Loss of E-cadherin promotes...

metastasis.

5

Desmosome (macula adherens)

structural support via keratin interactions

6

Autoantibodies to the desmosome cause...

pemphigus vulgaris.

7

Gap junction

channel proteins called connexons permit electrical and chemical communication between cells

8

Integrins

membrane proteins that maintain the integrity of basolateral membrane by binding to collagen and laminin in the basement membrane

9

Hemidesmosome

connects keratin in basal cells to the underlying BM

10

Autoantibodies to the hemidesmosome leads to...

bullous pemphigoid (hemidesmosomes are down "bullo")

11

Anterior drawer sign tests for...

ACL injury.

12

Posterior drawer sign tests for...

PCL injury.

13

Valgus stress (abduction) tests for....

MCL injury.

14

Varus stress tests for (adduction)....

LCL injury.

15

McMurray test

pain on external rotation = medial meniscus pain on internal rotation = lateral meniscus

16

Unhappy Triad

injury due to lateral force applied to planted leg; consists of damage to ACL, MCL and medial meniscus (or lateral meniscus)

17

Pudendal nerve block is given....

to relieve the pain of delivery into the ischial spine.

18

Rotator Cuff Muscles

Supraspinatus Infraspinatus Teres minor Subscapularis

19

Supraspinatus

-suprascapular nerve -abducts arm initially -most common rotator cuff injury

20

Infraspinatus

-suprascapular nerve -laterally rotates arm -pitching injury

21

Teres minor

-axillary nerve -adducts and laterally rotates arm

22

Subscapularis

-subscapular nerve -medially rotates and adducts arm

23

The most commonly fractured carpal bone is...

the scaphoid bone and it is prone to avascular necrosis due to retrograde blood supply. It can be palpated in the anatomical snuff box.

24

Dislocation of the lunate may cause...

acute carpal tunnel.

25

A fall on an outstretched hand that damages the hook of hamate can cause...

ulnar nerve injury.

26

Carpal Tunnel Syndrome

entrapment of median nerve leading to parestesia, pain and numbness

27

Guyon Canal Syndrome

compression of the ulnar nerve classically seen in cyclists

28

Erb Palsy is an injury of the...

upper trunk caused by lateral traction on infant's neck during delivery or trauma in adults.

29

Erb Palsy Muscle/Functional Deficits

Deltoid/Supraspinatus - abduction (arm hangs by side) Infraspinatus - lateral rotation (arm is medially rotated) Biceps brachii - flexion, supination (arm extended and pronated)

30

Klumpke Palsy is an injury of the....

lower trunk due to upward force on infant arm during delivery or adult trauma.

31

Klumpke Palsy Muscle/Functional Deficits

total claw hand due to intrinsic hand muscle deficits

32

Thoracic Outlet Syndrome is a....

compression of lower trunk and subclavian vessels due to a cervical rib injury or a Pancoast tumor.

33

Thoracic Outlet Syndrome has the same deficits as...

Klumpke's palsy.

34

Winged Scapula is an injury of...

the long thoracic nerve due either axillary node dissection after masectomy or stab wounds.

35

Winged Scapula Muscle/Functional Deficits

Serratus Anterior = cannot abduct arm above a horizontal position

36

Causes of injury to the axillary nerve (C5-C6)

fractured surgical neck of humerus; anterior dislocation of the humerus

37

Presentation of axillary nerve injury

-flattened deltoid -loss of arm abduction past 15 degrees -loss of sensation over delt and lateral arm

38

Cause of injury to musculocutaneous nerve (C5-C7)

upper trunk compression

39

Musculocutaneous Injury Presentation

-loss of forearm flexion/supination -loss of sensation over lateral forearm

40

Cause of injury to Radial nerve (C5-T1)

-midshaft fracture of humerus -compression of axilla due to crutches or sleeping with arm over chair

41

Presentation of radial nerve injury

-wrist drop -decreased grip strength -loss of sensation over posterior arm/forearm and dorsal hand

42

Cause of injury to Median nerve (C5-T1)

-supracondylar fracture of humerus -carpal tunnel syndrome or wrist laceration

43

Presentation of Median nerve injury

-ape hand and pope's blessing -Tinel sign (tingling on percussion) -loss of sensation over thenar eminence and dorsal/palmar aspects of lateral 3.5 fingers

44

Cause of injury to the Ulnar nerve (C8-T1)

fracture of the medial epicondyle of the humerous or fractured hook of hamate

45

Ulnar nerve injury presentation

-ulnar claw -loss of sensation over medial 1.5 fingers including hypothenar eminence

46

Injury to the recurrent branch of the median nerve

superficial palm laceration

47

Presentation of recurrent median nerve injury

ape hand -loss of thenar musclegroup -no loss of sensation

48

Interosseous Muscles DAB PAD

Dorsals ABduct Palmars ADduct

49

Lumbrical muscles act to...

flex and the MCP and extend at the PIP and DIP.

50

Obturator (L2-L4) injury is due to...

pelvic surgery and leads to decreased thigh sensation and decreased adduction.

51

Femoral (L2-L4) injury is due to...

pelvic fracture and leads to decreased thigh flexion and leg extension.

52

Common peroneal (L4-S2) injury is due to...

trauma or compression of the lateral aspect of the leg or fibular neck fracture.

53

Common peroneal injury presents with...

foot drop and loss of sensation on dorsum of foot

54

Tibial injury (L4-S3) can be due to...

knee trauma, baker cyst or tarsal tunnel syndrome.

55

Tibial injury presents with...

inability to curl toes and loss of sensation on the sole of the foot; if lesion is proximal, foot loses inversion and plantar flexion

56

Superior gluteal nerve (L4-S3) injury is due to...

posterior hip dislocation or polio.

57

Superior gluteal injury presents with..

Tendelenburg gait.

58

Trendelenburg gait is when...

the pelvis tilts because the weight-bearing leg cannont maintain alignment of the pelvis through hip abduction

59

In Trendelenburg gait, the lesion is...

contralateral to the side of the hip that drops.

60

Inferior gluteal nerve injury is due to...

posterior hip dislocation.

61

Inferior gluteal nerve presentation

difficulty climbing stairs, rising from seated position; loss of hip extension

62

The sciatic nerve splits into...

the common peroneal and tibial.

63

Axilla/Lateral Thorax nerve and artery

long thoracic n. and lateral thoracic a.

64

Surgical neck of humerus nerve and artery

axillary n and posterior circumflex a.

65

Midshaft of humerus nerve and artery

radial n and deep brachial a.

66

distal humerus/cubital fossa nerve and artery

median n and brachial a.

67

Popliteal fossa nerve and artery

tibial n and popliteal a.

68

medial malleolus nerve and artery

tibial n and posterior tibial a.

69

Type 1 Muscle Features

-slow twitch -red fibers (from incresaed mitochondria/myoglobin) -increased oxidative phosphorylation --> sustained contraction

70

Type 2 Muscle Featured

-fast twitch -decreased mitochondria/myoglobin (white fibers) -increased anaerobic glycolysis

71

Weight training results in...

hypertrophy of fast-twitch muscle fibers.

72

Endochondral ossification

cartilaginous model of bone is first made by chondrocytes; osteoclasts and osteoblasts later replace with woven bone and then remodel to lamellar bone

73

Endochondral ossification occurs in...

bones of the axial and appendicular skeleton and at the base of the skull

74

Membranous ossification

woven bone is formed directly without cartilage; later remodeled to lamellar bone

75

Membranous ossification occurs at...

bones of calvarium and facial bones

76

Osteoblasts act to...

build bone by secreting collagen and catalyzing mineralization.

77

Osteoblasts differentiate from...

mesenchymal stem cells in the periosteum.

78

Osteoclasts are...

multinucleated cells that dissolve bone by secreting acid and collagenases.

79

Osteoclasts differentiate from...

monocytes/macrophages.

80

Estrogen inhibits...

apoptosis of osteoblasts and promotes apoptosis of osteoclasts.

81

Under estrogen deficiency, bone experiences...

excess remodeling cycles and resorption leading to osteoporosis.

82

Achondroplasia is...

failure of longitudinal bone growth leading to short limbs.

83

In achondroplasia, membranous ossification is...

not affective leading to rather large head compared to limbs.

84

Achondroplasia occurs because...

constitutive activation of FGF3 inhibits chondrocyte proliferation.

85

Osteoporosis is...

loss of trabecular bone mass despite normal bone mineralization and lab values (Ca2+ and PO43-)

86

Diagnosis of osteoporosis is with...

a bone mineral density test (DEXA) with a T-score of

87

Type I Osteoporosis Features

-postmenopausal -increased bone resoprtion due to decreased estrogen levels -femoral neck fracture, distal radius fracture

88

Type II Osteoporosis Features

-senile osteoporosis -men and women >70

89

Treatment for Type II Osteoporosis

-Bisphosphonates -pulsatile PTH -SERMs -Denosumab

90

Osteopetrosis is..

failure of normal bone resorption due to defective osteoclasts resulting in thickened bones prone to fracutre.

91

In osteopetrosis, bone fills the...

marrow space leading to pancytopenia and extramedullary hematopoeisis.

92

In osteopetrosis, osteoclasts have mutations that...

impair the ability of osteoclast to generate an acidic envirnoment necessary for bone resoprtion.

93

Osteopetrosis x-rays show...

bone in bone appearance.

94

Osteopetrosis can result in...

cranial nerve impingement and palsies as a result of narrowed foramina.

95

Osteomalacia/Rickets is due to...

Vitamin D deficiency. Defective mineralization/calcification of osteoid leads to soft bones that bow out.

96

Decreased vitamin D decreases....

serum calcium, which increases PTH which decresaes serum phosphate.

97

In osteomalacia/rickets, there is hyperactivity of osteoblasts leading to...

increased ALP.

98

Paget's diseases of bone is due to...

increase in both osteoblastic and osteoclastic activity.

99

Lab levels in Paget's

-calcium, phosphorus, PTH normal -increased ALP

100

Paget's demonstrates...

a mosaic pattern of woven and lamellar bone. See long bone chalk-stick fractures.

101

Paget's increases the risk of...

high-output heart failure and osteogenic sarcoma.

102

Signs of Pagets'

-increased hat size -hearing loss

103

Stages of Paget

1. Lytic (osteoclasts) 2. Mixed (osteoclasts and blasts) 3. Sclerotic (blasts) 4. Quiescent

104

Osteonecrosis can be caused by...

trauma, high dose corticosteroids, alcoholism and sickle cell.

105

The most common site for osteonecrosis is...

the femoral head due to insufficiency of medial circumflex femoral artery.

106

Giant Cell Tumor Features

-20-40 yrs old -located at epiphyseal end of long bones (often the knee) -benign -"soap bubble" appearance on xray -multinucleated giant cells

107

Osteochondroma features

-benign -males < 25 -mature bone w/ cartilagimous cap

108

Osteosarcoma Features

-bimodal distribution (10-20 yrs; > 65 yrs) -metaphysis of long bones (usually knee)

109

Predisposing factors for Osteosarcoma

-Paget disease of bone -bone infarcts -radiation -familial retinoblastoma -Li-Fraumeni

110

On x-ray, osteosarcoma shows...

Codman triangle or sunburst pattern.

111

Treatment of osteosarcoma

surgical en bloc resection and chemo

112

Ewing Sarcoma Features

-boys < 15 -commonly appears in diaphysis of long bones, pelvis, scapula and ribs -anaplastic small blue cell malignant tumor -early mets but responds to chemo -onion skin appearance -11;22 translocation

113

Chondrosarcoma Features

-malignant, cartilaginous -men 30-60 yrs -usually in pelvis, spine, scapula, humerus, tibia or femur -can result from osteochondroma (rare)

114

Chondrosarcoma appears as...

an expansile glistening mass within the medullary cavity

115

Osteoarthritis Etiology

mechanical - joint wear and tear destroys articular cartilage

116

Osteoarthritis Joint findings (6)

-subchondral cysts -sclerosis -osteophytes -eburnation -Heberden nodes (DIP) -Bouchard nodes (PIP)

117

Predisposing factors for osteoarthritis

-age -obesity -joint deformity -trauma

118

Classic Presentation of Osteoarthritis

Pain in weight-bearing joints after use; improves with rest. Knee cartilage loss begins medially (bowlegged). Noninflammatory

119

Treatment for Osteoarthritis

-NSAIDs -Intra-articular Glucocorticoids

120

Rheumatoid Arthritis Etiology

-autoimmune (inflammatory destruction of synovial joionts) -mediated by cytokines and type III and type IV HSR

121

Joint findings in RA (5)

-pannus formation (MCP, PIP) -rheumatoid nodules (fibrinoid necrosis) -ulnar deviation of fingers -subluxation -Baker cyst (popliteal foss)

122

Predisposing Factors for RA

-females -rheumatoid factor (anti-IgG antibody) -anti-cyclic citrullinated peptide -HLA-DR4

123

Classic Presentation of RA

-morning stiffness > 30 minutes -improves with use -symmetric -systemic symptoms (fever, fatigue, pleuritis, pericarditis)

124

Treatment for RA

-NSAIDs -glucocorticoids -disease-modifying agents (methotrexate, sulfasalazine, TNF-alpha inhibitors)

125

Sjogren syndrome is an...

autoimmune disorder characterized by destruction of exocrine glands (esp. lacrimal and salivary).

126

Sjogren syndrome predominantly affects...

females 40-60 yrs old.

127

Findings of Sjogren syndrome

-xerophthalmia -xerostomia -presence of anti-nuclear antibodies (SS-A and SS-B) -bilateral parotid enlargement

128

Xerophthalmia is...

decreased tear production and corneal damage

129

Xerostomia is...

decreased saliva production

130

Complications of Sjogren Syndrome

-dental caries -MALT lymphoma

131

Gout is...

acute inflammatory monoarthritis caused by precipitation of monosodium urate crystals in the joints.

132

Gout is associated with...

hyperuricemia which can be caused by underexcretion of uric acid (90%) or overproduction.

133

Overproduction of uric acid is seen in...

Lesch-Nyhan syndrome, increased PRPP, increased cell turnover and von Gierke disease.

134

Underexcretion of uric acid can be caused by...

thiazide diuretics.

135

In gout, the crystals are...

needle shaped and negatively birefringent (yellow under parallel light and blue under perpendicular light).

136

symptoms of gout

-asymmetric -swollen, red, painful joint -tophus formation

137

Classic manifestation of gout is...

painful MTP joint of the big toe (podagra).

138

Acute attacks of gout tend to occur after...

a large meal or alcohol consumption (alcohol competes for the same excretion sites as uric acid in the kidney).

139

Treatment of acute gout

-NSAIDs -Glucocorticoids -Colchicine

140

Treatment of chronic gout

-xanthine oxidase inhibitors (allopurinol or febuxostat)

141

Pseudogout presents with...

pain and effusion in a joint caused by deposition of calcium pyrophosphate crystals in the joint space.

142

On x-ray, pseudogout shows...

chondrocalcinosis.

143

Pseudogout forms...

basophilic, rhomboid crystals athat are weakly positively birefringent.

144

Features of Pseudogout

-large joints (knee) - >50 yrs

145

Diseases associated with pseudogout include...

hemochromatosis, hyperparathyroidism, and hypoparathyroidism.

146

Treatment for Pseudogout

-NSAIDs -Colchicine

147

Common causes of infectious arthritis are...

S. aureus, Streptococcus and N. gonorrhaeae.

148

Gonococcal arthritis is an...

STD that presents as a migratory arthritis with an asymmetric pattern. S = synovitis (knee) T = tenosynovitis (hand) D = dermatitis (pustules)

149

Seronegative Spondyloarthropaties are...

arthritis wihtout rheumatoid factor and a strong association with HLA-B27.

150

Types of Seronegative Spondyloarthropathies (PAIR)

P = Psoriatic arthritis A = Ankylosing spondylitis I = Inflammatory bowel disease R = Reactive Arthritis

151

Psoriatic Arthritis Features

-joint pain/stiffness with psoriasis -asymmetric -dactylitis (sausage fingers) -"pencil in cup" on xray

152

Ankylosing spondylitis Features

-chronic inflammatory disease of the spine and sacroiliac joints -ankylosis (fusion of joints), uveitis and aortic regurgitation -bamboo spine on xray

153

Inflammatory Bowel Disease

-Crohn's and UC are often accompanied by ankylosing spondylitis or peripheral arthritis

154

Reactive Arthritis Class triad

-conjunctivits (and anterior uveitis) -Urethritis -arthritis (can't see, can't pee, can't bend my knee)

155

Reactive arthritis is usually due to...

post-GI (shigella, salmonella, yersinia or campylobacter) or chlamydia infxns.

156

Classic Presentation of Systemic Lupus Erythematous (SLE)

-rash -joint pain -fever -female of reproductive age -African descent

157

SLE is associated with...

Libman-Sacks endocarditis and Lupus Nephritis.

158

Libman-Sacks is...

a wart-like vegetation on both sides of a valve.

159

Lupus nephritis is...

Type III HSR -nephritic: diffuse proliferative glomeurlonephritis -nephrotic: membranous glomeulonephritis

160

Common causes of death in SLE

-CV disease -Infxns -Renal disease

161

Lupus Findings

1. ANA (sensitive, not specific) 2. anti-dsDNA Abs (specific) 3. Anti-Smith antibodies (specific) 4. Antihistone Abs (sensitive for drug-induced lupus) 5. Anticardiolipin Abs 6. decresed C3, C4 and CH50 due to immune complex formation

162

Treatment of SLE

-NSAIDs -Steroids -Immunosuppressants -Hydroxychloroquine

163

Sarcoidosis is characterized by...

immune-mediated, non-caseating granulomas and elevated ACE levels.

164

Sarcoidosis is common in...

balck females.

165

Sarcoidosis is often asymptomatic except for...

enlarged LNs.

166

Findings of Sarcoidosis on CXR are...

bilateral hilar adenopathy and reticular opacities.

167

Sarcoidosis is associated with...

restrictive lung disease (interstitial fibrosis), erythema nodosum, lupus pernio, Bell palsy, epithelioid granulomas (w/ Schaumann and asteroid bodies), uveitis and hypercalcemia.

168

Hypercalcemia in sarcoidosis is due to...

increased 1alpha-hydroxylase mediated Vit. D activation in macrophages.

169

Treatment for Sarcoidosis is....

steroids.

170

Polymyalgia rhematica symptoms are...

pain/stiffness in shoulders/hips often with fever, malaise and weight loss.

171

Polymyalgia rheumatica does not cause...

muscular weakness.

172

Polymyalgia rheumatica is common in...

women older than 50.

173

Polymyalgia rheumatica is associated with...

temporal (giant cell) arteritis.

174

Findings of Polymyalgia rheumatica

-increased ESR -increased CRP -normal CK

175

Treatment of Polymyalgia rheumatica

low-dose corticosteroids

176

Fibromyalgia is most commonly seen in...

females 20-50 yrs old. It is chronic musculoskeletal pain associated with stiffness, paresthesias, poor sleep and fatigue.

177

Fibromyalgia treatment

-regular exercise -antidepressants -anticonvulsants

178

Polymyositis is...

progressive, symmetrical proximal muscle weakness characterized by endomysial inflammation with CD8 T cells. Most often involves the shoulders.

179

Dermatomyositis is...

similar to polymositis but also has a rash, Gottron papules, heliotrope rash. (shawl and face rash and mechanic's hands)

180

Dermatomyositis has increased risk of...

occult malignancy.

181

Dermatomyositis pathology

-perimysial inflammation and atrophy with CD4 T cells

182

Findings of Polymyositis and Dermatomyositis

-increased CK -positive ANA -positive anti-Jo-1 -positive anti-SRP -positive anti-Mi-2 Abs

183

Treatment of Dermatomyositis and Polymyositis

steroids.

184

Pathophysiology of Myasthenia gravis

autoantibodies to postsynaptic ACh receptor

185

Clinical findings of myastenia gravis

ptosis, diplopia, weakness *worsens with muscle use

186

Myasthenia gravis is associated with...

thymoma and thymic hyperplasia

187

In myasthenia gravis, AChE inhibitor will...

reverse symptoms.

188

Pathophysiology of Lambert-Eaton Myasthenic Syndrome

autoantibodies to presynaptic Ca2+ channels leading to decreased ACh release

189

Lambert-Eaton Clinical Findings

-proximal muscle weakness -autonomic symptoms (dry mouth, impotence) *improves with muscle use

190

Lambert-Eaton is associated with...

small cell lung cancer.

191

Myositis Ossificans is...

metaplasia of skeletal muscle to bone following muscular trauma.

192

Scleroderma is...

excessive fibrosis and collagen deoposition throughout the body. commonly sclerosis of the skin, mainfesting as puffy and taut skin. 75% female.

193

Most common cause of death in scleroderm is...

pulmonary sclerosis.

194

Diffuse Scleroderma

-widespread skin involvement -rapid progression -early visceral involvement -associated with anti-Scl-70 Ab (anti-DNA topoisomerase I Ab)

195

Limited Scleroderma

-skin involvement limited to fingers and face -CREST involvement -anit-Centromere Ab

196

CREST

C = Calcinosis R = Raynoaud E = Esophageal dysmotility S = Sclerodactyly T = Telangiectasia

197

A macule is a...

flat lesion with well-circumscribed chin in skin color < 1 cm Ex. freckle, labial macule

198

A patch is...

a macule > 1 cm. Ex. large birthmark (congenital nevus)

199

A papule is...

an elevated, solid skin lesion < 1 cm. Ex. mole (nevus), acne

200

A plaque is...

a papule > 1 cm. Ex. Psoriasis

201

Vesicle

small fluid-containing blister < 1 cm Ex. chickenpox, shingles

202

Bulla

large fluid containing blister > 1 cm Ex. bullous pemphigoid

203

Pustule

vesicle containing pus ex. pustular psoriasis

204

Wheal

transient smooth papule or plaque Ex. hives (urticaria)

205

Scale

flaking off of stratum corneum Ex. eczema, psoriasis, SCC

206

Crust

dry exudate Ex. impetigo

207

Hyperkeratosis

increased thickness of the stratum corneum Ex. psoriasis, calluses

208

Parakeratosis

hyperkeratosis with retention of nuclei in stratum corneum Ex. psoriasis

209

Spongiosis

epidermal accumulation of edematous fluid in the intercellular spaces Ex. eczematous dermatitis

210

Acantholysis

separation of epidermal cells Ex. pemphigus vulgaris

211

Acanthosis

Epidermal hyperplasia (increased spinosum) Ex. Acanthosis nigricans

212

Albinism is...

normal melanocyte number with decreased melanin production due to decreased tyrosinase activity or defective tyrosine transport (or by failure of neural crest cell migration)

213

Albinism has an increased risk of...

skin cancer.

214

Melasma (cholasma) is...

hyperpigmentation associated with pregnancy or OCP use

215

Vitiligo

irregular areas of complete depigmentation caused by autoimmune destruction of melanocytes

216

Verrucae

warts caused by HPV; soft, tan cauliflower-like papules

217

Histological changes of verrucae

epidermal hyperplasia, hyperkeratosis, koilocytosis

218

Melanocytic nevus

common mole; melanoma can arise in congenital or atypical moles *intradermal nevi are papular **junctional nevi are flat molecules

219

Urticaria

hives; pruritic wheals that form after mast cell degranulation

220

Urticaria is characterized by...

superficial dermal edema and lymphatic channel dilation.

221

Ephelis

freckle; normal number of melanocytes but increased melanin pigment

222

Atopic dermatitis (eczema)

pruritic eruption commonly on skin flexures; often associated with other atopic diseases (asthma, allergic rhinits)

223

Atopic dermatitis usually starts on...

the face in infancy and often appears in the antecubital foassae after.

224

Allergic Contact Dermatitis

Type IV HSR that follows exposure to teh allergen; lesions occur at the site of contact (ex. nickel, poison ivy, neomycin)

225

Psoriasis

papules and plaques with silvery scaling (knees and elbows); acanthosis with parakeratotic scaling increased spinosum, decreased granulosm Auspitz sign

226

Psoriasis can be associated with...

nail pitting and psoriatic arthritis.

227

Seborrheic keratosis is...

flat, greasy, pigmented squamous epithelial proliferation with keratin-filled cysts (horn cysts); look "stuck on" *common benign neoplasm of older people

228

Seborrheic keratosis lesions occur on...

the head, trunk and extremities.

229

Lese-Trelat sign is...

a sudden appearance of multiple seborrheic keratoses, indicating an underlying malignancy (GI, lymphoid).

230

Impetigo

superficial skin infection from S. aureus or S. pyogenes very infectious ***honey-colored crusting

231

Bullous impetigo has...

bullae and is usually due to S. aureus.

232

Cellulitis is...

acute, painful spreading infxn of the dermis and subcutaneous tissue.

233

Cellulitis is usually due to...

S. pyogenes or S. aureus.

234

Cellulitis often starts with...

a break in thes kin from trauma or another infxn.

235

Necrotizing fasciitis is...

a deeper tissue injury usually from anaerobic bacteria or S. pyogenes.

236

Necrotizing fasciitis results in....

crepitus from methane and CO2 production. "flesh-eating bacteria"

237

Necrotizing fasciitis causes...

bullae and a purple color to the skin.

238

Staphylococcal scalded skin syndrome is due to....

an exotoxin that destroys keratinocyte attachments in the stratum granulosum only.

239

Staph scalded skin syndrome is characterized by...

fever and erythematous rash with sloughing of the upper layers of the epidermis that heals completely.

240

Hairy leukoplakia is...

a white, painless plaque on the tongue that cannot be scraped off.

241

Hairy leukoplakia is mediated by...

EBV and it occurs in HIV + patients.

242

Pemphigus vulgaris is a...

potentially fatal skin disorder with IgG antibody against desmoglein component of desmosomes. There is flaccid intraepidermal bullae caused by acantholysis; oral mucosa also involved.

243

Immunofluorescence of Pemphigus vulgaris reveals...

Abs around epidermal cells in a reticular pattern. (net-like)

244

Pemphigus vulgaris has a positive...

Nikolsky sign (separation of epidermis upon manual stroking of skin).

245

Bullous Pemphigoid is less severe....

than Pemphigus vulgaris. It involves IgG antibody against hemidesmosomes.

246

Bullous Pemphigoid shows....

tense blisters containing eosinophils that affect the skin but spare the oral mucosa.

247

Immunofluorescence of bullous pemphigoid reveals...

a linear pattern at the epidermal-dermal junction.

248

Bullous pemphigoid has a negative...

Nikolsky sign.

249

Dermatitis herpetiformis

pruritic papules, vesicles and bullae. Deposits of IgA at the tips of dermal papillae

250

Dermatitis herpetiformis is associated with...

celiac disease.

251

Erythema multiforme is associated with....

infections (mycoplasma pneumoniae, HSV) drugs (sulfa drugs, beta-lactams, phenytoin) cancers autoimmune disease

252

Erythema multiforme presents with...

multiple lesions - macules, papules, veiscles and target lesions.

253

Stevens-Johnson Syndrome is characterized by...

fever, bulla formation and necrosis, sloughing of skin, and a high mortality rate.

254

SJS typically involves...

2 mucous membranes (lips and mouth, etc.). Skin lesions appear like targets. Associated with drug rxn.

255

A more severe form of SJS is...

toxic epidermal necrolysis with more than 30% of the body involved.

256

Acanthosis nigricans is...

epidermal hyperplasia causing symmetrical, hyperpigmented, velvety thickening of skin, especially on neck or axilla.

257

Acanthosis nigricans is associated with...

hyperinsulinemia (diabetes, obesity, Cushing's) and visceral malignancy (gastric adenocarcinoma).

258

Actinic keratosis is....

premalignant lesions caused by sun exposure.

259

Actinic keratosis presents as...

small, rough, erythematous/brownish papules or plaques.

260

Risk of SCC with actinic keratosis is proportional to...

the degree of epithelial dysplasia.

261

Erythema nodosum is...

a painful, inflammatory lesion of subcutaneous fat, usually on anterior shins.

262

Erythema nodosum is often idiopathic but can be associated with...

sarcoidosis, coccidioidomycosis, histoplasmosis, TB, strep, leprosy and Crohn's.

263

6 Ps of Lichen Planus

pruritic purple polygonal planar papules plaques

264

Mucosal involvement with Lichen Planus manifests as...

Wickham striae (reticular white lines). Also sawtooth infiltrate of lymphocytes at the dermal-epidermal junction.

265

Lichen Planus is associated with...

Hep C.

266

Pityriasis rosea presents as...

a herald patch followed days later by christmas tree distribution of multiple plaques with collarette scale.

267

Course of Pityriasis rosea

self-resolving in 6-8 wks.

268

Sunburn causes...

DNA mutations, inducing apoptosis of keratinocytes.

269

UVA is dominant in...

tanning and photoagin.

270

UVB is dominant in...

sunburn.

271

Sunburn can lead to...

impetigo and skin cancer.

272

The most common skin cancer is...

basal cell carcinoma. It is found in sun-exposed areas of the body and is locally invasive but rarely metastasizes.

273

BCC presents with...

pink, pearly nodules, commonly with telangiectasias, rolled borders and central crusting/ulceration.

274

BCC can also appear as...

nonhealing ulcers with infiltrating growth or as a scaling plaque.

275

Histology of BCC shows...

palisading nuclei.

276

Squamous Cell Carcinoma is associated with...

excessive exposure to sunlight, immunosuppression, and arsenic.

277

SCC commonly appears on...

the face, lower lip, ears and hands. It is locally invasive, can spread to LNs but rarely metastasizes.

278

SCC appears as...

ulcerative red lesions with frequent scale. And chronic draining sinuses.

279

Histology of SCC shows...

keratin "pearls".

280

Melanoma has a significant risk of...

metastasis. Risk correlates with depth of tumor.

281

Tumor marker of melanoma

S-100

282

Melanoma is associated with...

sunlight exposure, fair-skinned persons are at increased risk.

283

ABCDEs of Melanoma

A = asymmetry B = border irregularity C = color variation D = diameter > 6 mm E = evolution over time

284

Melanoma is often driven by ...

an activating mutation of BRAF kinase.

285

Primary treatment of melanoma is...

excision with appropriately wide margins.

286

Metastatic or unresectable melanoma in pts with BRAF V600E mutation may benefit from...

vemurafenib, a BRAF kinase inhibitor.