MSS Pathology Flashcards
1
Q
What is Achondroplasia?
A
- Failure of longiudinal bone growth 9endochonrdal ossification)→ short limbs
- Membranous ossification is not affected→ large head relative to limbs
- Common cause of dwarfism
- Normal life span & fertility
2
Q
**Growth Factor involved in Achondroplaisa **
A
Constitutive activation of fibroblast GF receptor (FGFR3) acutally inhiits chondrocyte proliferation
3
Q
Pattern of Inheritance of Achondroplaisa
A
- AD inheritance
- 85% occur sporatidaclly & assoc w/ advanced paternal age
4
Q
What is Osteoporosis?
A
Trabecular (spongy) bone loses mass & interconnections despite normal bone mineralization & lab values ( serum Ca2+ & PO43-)
5
Q
What are Vertebral Crush Fractures?
A
- Acute back pain
- Loss of height
- Kyphosis
- Caused by osteoporosis
6
Q
What is Type I Osteoporosis?
A
- Postmenopausal: inc bone resportion d/t dec estrogen levels
- Femoral neck fracture, distal radius (Colles’) fractures
7
Q
What is Type II Osteoporosis?
A
- Senile osteoporosis
- Affects men & women >70 years of age
8
Q
Prophylaxis for Type II Osteoporosis
A
Regular wt bearing exercise & adequate Ca & Vit D intake throughout adulthood
9
Q
Tx for Osteoporosis Type II
A
- Estrogen (SERMs) &/or calcitonin
- Bisphosphonates or pulsatile PTH for severe cases
- Glucocorticoids are contraindicated
10
Q
What is Osteopetrosis?
A
Failure of normal bone resorption d/t defective osteoclasts→ thicekened, dense bones taht are prone to fracture
11
Q
What does Osteopetrosis look like?
A
Bone fills marrow space, causing pancytopenia, extramedullary hematopoiesis
12
Q
What do the mutations in Osteopetrosis do?
A
Impair ability of osteoclast to generate acidic environment necessary for resorption (e.g. carbonic anyhydrase II)
13
Q
Look of Osteopetrosis on X-ray
A
Bone-in-bone appearance
14
Q
Osteopetrosis can result in:
A
- Crainial nerve impingement
- Palsies as a result of narrowed formaina
15
Q
Tx for Osteopetrosis
A
BM transplant is potentialy curative as osteoclasts are derived from monocytes
16
Q
What can Vit D deficiency cause?
A
- Rickets in children
- Osteomalacia in adults
17
Q
Pathway of Vit D Deficiency
A
- dec Vit D→ dec serum Ca→ Inc PTH secretion → dec serum phosphate
- Hyperactivity of osteoclasts→ inc alk phos
- defective mineralization/ calcification of osteoid l/t soft bones that bow out
18
Q
What is Osteitits deformans?
A
- Pagent’s dz of bone
- Common, localized disorder of bone remodeling caused by inc both osteoblastic & osteoclastic activity
19
Q
Lab Values of Osteitis deformans
A
Normal serum Ca, P & PTH levels w/ inc ALP
20
Q
What does osteitis deformans look like?
A
- Mosaic (“woven”) bone pattern
- Long bone chalk-stick fractures
21
Q
What can Osteitis deformans cause?
A
- Inc blood flow from inc arteriovenous shunts may cause high-output HF
- Inc risk of osteogenic sarcoma
- Hat size can be Inc
- Hearing loss is common d/t auditory foramen narrowing
22
Q
What is osteitis fibrosa cystica?
A
- “Brown tumors” of hyperparathyroidism
- Inc serum Ca, ALP, PTH & dec P
23
Q
What is Polyostotic fibrous dysplasia?
A
Bone replaced by fibroblasts, collagem, & irregular bony trabeculae
24
Q
What is McCune-Albright Syndrome?
A
Form of polycystic fibrous dysplasia char by mulitple unilateral bone lesions assoc w/ endocrine ABN (precociou puberty) & café-au-lait spots
25
What are the 1º benign bone tumors?
* Giant cell tumor (osteoclastoma)
* Osteochondroma (exostosis)
26
What age group osteoclastoma occur?
20-40yo
27
What is Ostoclastoma?
Locally aggressive benign tumor ofent around the distal femur, proximal tibial region (knee)
28
Osteoclastoma appearance on X-ray
"Double bubble" or "soap bubble"
29
Histo of osteoclastoma
Spindle-shaped cells w/ multinucleated giant cells
30
What age does Osteochonroma occur?
Males \<25yo
31
What is Osteochondroma?
* Most common benign tumor
* Mature bone w/ cartilagenous cap
32
Where does Osteochondroma commonly originate?
Long metaphysis
33
What does Osteochondroma transform to?
Rare transformation to chondrosarcoma
34
What are the 1° malignant bone tumors?
* Osteosarcoma (osteogenic sarcoma)
* Ewing's sacroma
* Chondrosarcoma
35
Who gets Osteosacroma?
* Males\> females
* 10-20 yo
36
What are the predisposing factors to Osteosarcoma?
* Paget's dz of bone
* Bone infarcts
* Radiation
* Familial retinoblastoma
37
Characteristics of Osteosarcoma
* Metaphysis of long bones, often aroudn distal femur, proximal tibial region (knee)
* Codman's triangle (from elevation of periosteum or sunburst pattern on X-ray
38
Tx of Osteosarcoma
Aggressive, tx w/ surgical en bloc resection (w/ limb salvage) & chemotherapy
39
Who gets Ewing's Sarcoma?
Boys \<15yo
40
Where does Ewing's Sarcoma occur?
Commonly appears in diaphysis of long bones, pelvis, scapula & ribs
41
Histo of Ewing's Sarcoma
* Anaplastic small blue cell malignant tumor
* "Onion skin" appearance in bone
* (Going out for Ewing's & onion rings)
42
Prognosis of Ewing's Sarcoma
Extremely aggressive w/ early mets but responsive to chemo
43
What translocation is Ewing's Sacroma assoc w/?
t(11;22)
| (11+22=33 Patrick Ewing's jersey #)
44
Who gets Chonrosarcoma?
Men 30-60yo
45
Where is Chondrosarcoma located?
Pelvis, spine, scapula, humerus, tibia or femur
46
What is Chondrosarcoma?
* Malignant cartilaginous tumor
* May be of 1° origin or from osteochondroma
* Expansile glistening mass w/in the medullary cavity
47
Cause of Osteoarthritis
Mechanical- joint wear & tear destroys articular cartilage
48
Joint findings of Osteoarthritis
* Subchondral cysts
* Sclerosis
* Osteophytes (bone spurs)
* Eburnation (polished ivory-like appearance of bone)
* Bouchard's nodes (PIP)
* No MCP involvement
49
Predisposing factors of Osteoarthritis
* Age
* Obesity
* Joint deformity
50
Clinical Presentation of Osteoarthritis
* Pain in wt-bearing joints after use (at the end of the day) improving w/ rest
* Knee CT loss begins medially ("bowlegged")
* Noninflammatory
* No systemic sx
51
Tx of Osteoarthritis
NSAIDs & Intra-articular glucocorticoids
52
Cause of Rheumatoid arthritis
Autoimmune- inflammatory destruction of synovial joints. Type III hypersensitivity
53
Joint findings in RA
* Pannus formation in joints (MCP, PIP)
* SQ rheumatoid nodules (fibrinoid necrosis)
* Ulnar deviation of fingers subluxation
* Baker's cysts (in politeal fossa)
* No DIP involvement
54
Predisposing Factors of RA
* Females\> males
* 80% have + Rheumatoid factors (anti-IgG Ab)
* Anti-cyclic citrullinated peptide Ab is more specific
* Strong assoc w/ HLA-DR4
55
Clinical Presentation of RA
* Morning stiffness lasting \>30 min & improving w/ use
* Symmetric joint involvement
* Systemic sx- fever, fatigue, pleuritis, pericarditis
56
Tx of RA
* NSAIDs
* Glucocorticoids
* Dz-modifying agents (methotrexate, sulfasalazine, TNF-alpha inhibitors)
57
What is Sjögren's Syndrome?
Lymphocytic infiltration of exocrine glands, especially lacrimal & salivary
58
Classic Triad of Sjögren's Syndrome
* Xerophthalamia- dry eyes, conjuctivitis, "sand in my eyes"
* Xerostomia- dry mouth, dysphagia
* Arthritis
59
Characteristics of Sjögren's Syndrome
* Parotid enlargement
* inc risk of B-cell lymphoma
* Dental Caries
* Auto-Ab to ribonucleoprotein Ag: SS-A (Ro), SS-B (La)
* Assoc w/ rehumatoid arthritis
60
What is Gout?
* Precipitation of monosodium urate crystals into joints d/t hyperuricemia which can be caused by Lesch-Nyhan synd
* PRPP excess, dec excetion of uric acid (d/t thyazide diruetics)
* Inc cell turnover or von Gierke's dz
* 90% d/t underexcretion
* 10% d/t overproduction
61
What does Gout look like?
Crystals are needle shaped & negatively birefringemant= yellow crystals under parallel light
62
Sx of Gout
* Asymmetric join distribution
* Joint is swollen, red & painful
* Classic manifestation is painful MTP joint of the big toe (podagra)
* Tophus formation (often on external ear, olecranon bursa or Achilles tendon)
* Acute attack tends to occur after a large meal or alcohol consumption (alcohol metabolites compete for same excretion sites in kindney as uric acid, causing dec uric acid sec & subsequent bulidup in blood)
63
Tx of Gout
* _Acute_: NSAIDs (indomethacin), glucocorticoids
* _Chronic_: xanthine oxidase inhibitors (allopurinol, febuxostat)
64
Cause of Pseudogout
* Depostions of Ca pyrophosphate crystals w/in the joint space
* Usuallly affects large joints (classically the knee)
65
What does Pseudogout look like?
* Forms basophilic, rhomoid crystals that are weakly + birefringement
* Crystals are blue when parallel to the light
66
Who gets Pseudogout?
* \>50yo
* Effects both sexes equally
67
Tx of Pseudogout
* NSAIDs for sudden severe attacks
* Steroids
* Colchicine
68
Causes of Infectious Arthritis
* *S. aureus*
* *Streptococcus*
* *Niesseria gonorrheaoeae*
69
What is Infectious Arthritis?
Gonococcal arthritis is an STD that presents as a migratory arthritis w/ an asymmetric pattern
70
Sx of Infectious Arthritis
* Affected joint is swollen, red & painful
* **S**ynovitis (knee)
* **T**enosynovitis (hand)
* **D**ermatitis (pustules)
71
What is Osteonecrosis?
* Avascular necrosis
* Infarction of bone & marrow
* Pain assoc w/ activity
* MC site is femoral head
72
Causes of Osteonecrosis
* Trauma
* High-dose corticosteroids
* Alcoholism
* Sickle cell
73
What are Seronegative spondyloarthropathies?
* Arthritis w/o rheumatoids factor (no IgG Ab)
* Psoriatic arthritis
* Ankylosing spondylitis
* IBS
* Reactive arthritis (Reiter's synd)
74
What seronegative spondyloarthropathies asoc w/?
* HLA-B27 (gene that codes for HLA- MHC class I)
* Occurs more often in males
75
What is Psoriatic arthritis?
* Joint pain & stiffness seen in \<1/2 of pts w/ psoriasis
* Asymmetric & patchy involvement
* Dactylitis "sausage fingers"
* Pencil-in-cup deformity on X-ray
76
What is Ankylosing spondylitis?
Chronic inflam dz of spine & sacroiliac joints→ ankylosis (stiff spine d/t fusion of joints), uveitis & aoritic regurg. Bamboo spine (vertebral fusion)
77
What is IBS?
Chron's dz & UC are often accompanied by ankylosing spondylitis or peripheral arthritis
78
Reactive arthritis (Reiter's Synd) Triad
* **C**onjunctivitis & anterior uveitis
* **U**rethritis
* **A**rthritis
* "Can't see, can't pee, can't climb a tree"
* Post GI or chlamydia infections
79
Who gets SLE?
* 90% are female
* 14-45yo
* MC & severe in black females
80
Clinical presentation of SLE
* Fever, fatigue, wt loss
* **Libman-sacks endocarditis** (verrucous war-likem sterile vegetations on both sides of valve)
* Hilar adenopathy
* Raynaoud's phenomenon
81
What is the common COD in SLE?
Nephritis-Diffuse proliferative glomerulonephritis (if nephrotic)
82
What causes false + on the syphillis test (RPR/VDRL)?
Antiphospolipid Ab's which cross-react w/ cardiolipin used in tests
83
What do SLE lab tests detect?
* **Antinuclear Ab's** (ANA)- sensitive, (1° screening) but not specific for SLE
* **Ab's to ds-DNA** (anti-dsDSA)- very specific, poor prognosis,
* **Anti-Smith Ab's** (anti-Sm)- very specific, but not prognostic
* **Antihistone Ab's**- more sensitive for drug-induced lupus
84
I'M DAMN SHARP
(SLE characteristics)
* **I**g's (anti-dsDNA, anti-Sm, antiphospholipid)
* **M**alar rash
* **D**iscoid rash
* **A**ntinuclear Ab
* **M**ucositis (oropharyngeal ulcers)
* **N**eurologic disorders
* **S**erositis (pleuritis, pericarditis)
* **H**ematologic disorders
* **A**rthritis
* **R**enal disorders
* **P**hotosensitivity
85
Characteristics of Sacroidosis
* Immune-mediated, widesspread noncaseating granulomas & elevated serum ACE levels
* Often asx except for enlarged LN
* Common in black females
86
What is Sarcoidosis assoc w/?
* Restrictive lung dz (interstitial fibrosis)
* Erythema nodosum
* Bell's palsy
* Epi granulomas containing microscopic Schaumann & asteroid bodies
* Uveitis
* Hyper-Ca (d/t elevated 1-alpha-med vit D activation in epitheloid macro)
87
Tx of Sarcoidosis
Steroids
88
Sx of Polymyalgia rheumatica
* Pain & stiffness in shoulds & hips
* Fever
* Malaise
* Wt loss
* Does not cause muscle weakness
89
Who gets Polymyalgia rheumatica?
MC in women \>50yo
90
What is Polymyalgia rheumatica?
Temporal (giant cell) arteritis
91
Findings in Polymyalgia rheumatica
Inc ESR & normal CK
92
Tx of Polymyalgia rheumatica
Rapid response to low-dose corticosteroids
93
Who gets Fibromyalgia?
MC seen in women 20-50yo
94
What is Fibromyalgia?
Chronic, widespread MSS pain assoc w/ stiffness, paresthesia, poor sleep & fatigue
95
What is Polymyositis?
Progressive symmetric proximal muscle weakness, characteristized by endomysial inflam w/ CD8+ T cells. Most often involves shoulders
96
What are the characteristics of Dermatomyositis?
* Similar to polymyositis
* Malar rash (similar to SLE)
* Gottron's papules
* Heliotrope rash
* "Shoulder & face rash
* "Mechanic hands"
97
What is dermatomyositis?
Perimysial inflam & atrophy w/ CD4+ T cells
98
What does Dermatomyositis inc the risk of?
Occult Malignancy
99
Findings in Polymyositis/Dermatomyositis
* Inc CK
* + ANA
* + anti-Jo-1 Ab's
100
Tx of Polymyositis/dermatomyositis
Steroids
101
What is the freq of Myasthenia gravis?
MC NMJ disorder
102
What is the pathophysiology of Myasthenia gravis?
Auto-Ab's to postsynaptic ACh receptors
103
What does AChE inhibitor admin do in Myasthenia gravis?
Reversal of sx
104
Clinical characterisitics of Myastenia gravis
* Ptosis
* Diplopia
* Weakness
* Worsens w/ muscle use
105
What is Myasthenia gravis assoc w/?
Thymoma & thymic hyperplasia
106
Freq of Lmabert-Eaton myasthenic synd
Uncommon
107
Pathophysiology of Lamber-Eaton myasthenic synd
Auto-Ab's to presynaptic Ca2+ channel→ dec ACh release
108
Clinical sx of Lamber-Eaton Synd
Proximal muscle weakness that improves w/ muscle use
109
What is Lamber-Eaton synd assoc w/?
Small cell lung cancer
110
What does AChE inhibitor admin in Lamber-Eaton Synd do?
No effect
111
What is Myositis ossificans?
Metaplasia of skm to bone following muscular trauma
112
Where is Myositis ossificans most often seen?
Upper or lower extremity
113
How does Myositis ossificans present?
Suspicous "mass" at site of known trauma or as incidental finding on radiography
114
What is Scleroderma (systemic sclerosis)?
Excessive fibrosis & collagen deposition throughout the body
115
How does Scleroderma of skin commonly present?
Sclerosis of skin, manifesting as puffy & taut skin w/ absence of wrinkles
116
What organ systems does slceroderma affect?
* Renal
* Pulmonary (most likely COD)
* CV
* GI system
117
Who gets scleroderma?
75% female
118
What is Diffuse scleroderma?
Widespread skin involvement, rapid progression, early visceral involvement
119
What is Diffuse scleroderma assoc w/?
anti-Scl-70 Ab (anti-DNA topoisomerase I Ab)
120
Clinical sx of CREST synd
* **C**alcinosis
* **R**eaynaud's phenomenon
* **E**sophageal dysmotility
* **S**clerodactyly
* **T**elangiectasia
* Limited skin involvement often confined to fingers & face
121
What is the clincial course of CREST synd?
More benign clinical course
122
What is CREST synd assoc w/?
Anti-**C**entromere Ab ( **C** fo **C**REST)
123
What is a macule?
Flat lesion w/ well-circumscried change in skin color \<5mm. Ex) freckle, labial macule
124
What is a Patch?
macule \>5mm Ex) large brithmark (congenital nevus)
125
What is a papule?
Elevated solid skin lesion \< 5mm
Ex) Mole (nevus), acne
126
What is a Plaque?
Papule \>5mm
ex) psoriasis
127
What is a vesicle?
Small fluid-containing blister \<5mm
ex) Chickenpox (varicella), shingles (zoster)
128
What is Bulla?
Large fluid-containing blister \>5mm
ex) Bullous pemphigoid
129
What is a pustule?
Vesicle containing pus
ex) Pustular psoriasis
130
What is a Wheal?
Transient smooth papule or plaque
ex) Hives (urticaria)
131
What is a Scale?
Flaking off of stratum corenum
ex) eczema, psoriasis, SCC
132
What is a Crust?
Dry exudate
ex) Impetigo
133
What is Hyperkaratosis?
Inc thickness of stratum corneum
ex) psoriasis
134
What is parakeratosis?
Hyperkaratosis w/ retention of nuclei in stratum corneum
ex) psoriasis
135
What is Acantholysis?
Separation of epidermal cells
ex) Pemphigus vulgaris
136
What is Acanthosis?
Epidermal hyperplasia (inc spinosum)
ex) Acanthosis nigricans
137
What is Dermatitis?
Inflam of the skin
ex) Atopic dermatitis
138
What is Albinism
Normal melanocyte # w/ dec melanin production d/t dec tyrosine activity. Can also be caused by failure of neural cress cell migration during dev
139
What is Melasma (chloasma)?
Hyperpigmentation assoc w/ pregnancy ("mask of preg") or OCP use
140
What is Vitiligo?
Irreg areas of complete depigmentation
141
What causes Vitiligo?
Dec in melanocytes
142
What are Verrucae?
Warts, Condyloma acuminatum on genitals
143
What causes Verrucae?
HPV
144
What do Verrucae look like?
Soft, tan-colored, cauliflower-like papules
145
Histo of verrucae
Epidermal hyperplasia, hyperkartosis, koilocytes
146
What are Melanoctic nevus?
Common mole
147
Prognosis of Melanocytic nevus
Benign, but mealonoma can arise in congenital or atypical moles
148
What does Intradermal nevi look like?
Papular
149
What do Junctional nevi look like?
Flat macules
150
What is Urticaria?
Hives; pruritic wheals that form after mast cell degranulation
151
What is Ephelis?
* Freckle
* Normal # of melanocytes
* Inc melanin pigment
152
What is Atopic dermatitis (eczema)?
Pruritic eruption, commonly on skin flexures. Us. on the face in infancy & antecubital fossae therafter
153
What is Atopic dermatitis assoc w/?
Other atopic dz- asthma & allergic rhinitis
154
What is allergic contact dermatitis?
Type IV hypersensitivity reaction that follows exposure to allergen. Lesions occur at contact site (nickle, poision ivy, neomyocin)
155
What is Psoriasis?
Papules & plaques w/ silvery scaling, esp on knees & elbows
156
Histo of Psoriasis
Acanthosis w/ perakeratotic scaling (nuclei still in stratum corneum). Inc stratum spinousm & dec stratum granulosum
157
What is Auspitz sign?
Pinpoint bleeding spots from exposure of dermal papillae when scales are scraped off
158
What is Psoriasis assoc w/?
Nail pitting & psoriatic arthritis
159
What is Seborrheic keratosis?
Flat, greasy pigmented squamous epi prolif w/ keratin-filled cysts (horn cyts). Looks "stuck on"
160
Where do Seborrheic keratosis lesions occur?
Head, trunk & extremities
161
Who gets Seborrheic keratosis?
Common benign neoplasm of older persons
162
What is Leser-Trélat sign?
Sudden appearance of multiple seborrheic keratoses, indicating an underlying malignancy (GI, lymphoid)
163
What is Pemphigus vlugaris?
Potentially fatal autoimmune skin disorder w/ IgG Ab against desmoglein 3 (1 &/or 3), a part of desmosomes (needed for cell adhesion)
164
What does immunofluorescense of Pemphigus vulgaris reveal?
Ab's around epidermal cells in a reticular or netlike pattern
165
What is Acantholysis in Pemphigus vulgaris look like?
Intraepidermal bullae causing flaccid blister involving the skin & oral mucosa
166
What is Nikolsky's sign?
Separation of epidermis upon manual stroking of skin. + in Pemphigus vulgaris
167
What is bullous pemphigoid?
Autoimmune disorder w/ IgG ab against hemidesmosomes (epi BM; Ab's are "bullow" the epidermis)
168
What does Bullous pemphigoid show on immunoflurorescence?
Linear immunofluorescence
169
What are the clinical characteristics of Bullous pemphigoid?
* Eosinophils w/in the tense blisters.
* Similar to but less severe than pemphigus vulgaris- affects skin but spares oral mucosa.
* Negative nikolsky's sign
170
What is Dermatis herpetiformis?
Pruritic papules, vesicles & bullae. Deposits of IgA at the tips of dermal papillae
171
What is Dermatitis herpetiformis assoc w/?
Celica dz
172
What is Erythema mutliforme assoc w/?
Infections (Mycoplasma pneumonia, HSV), cancers & autoimmune dz
173
How does erythema muliforme present?
Multiple types of lesions- macules, papules, vesicles & target lesions
174
What does a target ring look like?
Targets w/ muliple rings & a dusky center showing epi disruption
175
What is Stevens-Johnson synd characterized by?
* Fever
* Bulla formation
* Necrosis
* Sloughing of skin
* High mortality rate
176
What does Stevens-Johnson synd look like?
Typicaly 2 mucous mem involved & skin lesions maybe appear liek targets as seen in erythema multiforme
177
What is Stevens-Johnson synd assoc w/?
Adverse drug reaction
178
What is Toxic epidermal necrolysis?
A more severe form of Stevens-Johnson synd w/ \>30% of the body surface area involved. Destroys the epidermal-dermal junction.
179
What is acanthosis nigricans?
Epidermal hyperplasia cuasing symmetrical, hyperpigmented, velvety thickening of skin, esp on neck or in axilla
180
What is aconathosis nigricans assoc w/?
Hyperinsulinemia (DM, obesity, Cushing's synd) & visceral malignancy
181
What is actinic keratosis?
premalignant lesions caused by sun exposure
182
What does actinic keratosis look like?
Small, rough, erythematous or brownish papules or plaques
183
What is actinic keratosis a risk for?
Risk of SCC is proportional to degree of epi dysplasia
184
What is erythema nodosum?
Inflam lesions of SQ fat, usually on anterior shins
185
What is erythema nodosum assoc w/?
Sarcoidosis, coccidioidomyocosis, histoplasmosis, TB, strep infections, leprosy & Chron's dz
186
What are the 6 **P**'s of Lichen Planus?
**P**ruritic, **P**urple, **P**olygonal **P**lanar **P**aules & **P**laques
187
Histo of Lichen Planus
Sawtooth infilitrate of lymphocytes at dermal-epidermal junction
188
What is Lichen Planus assoc w/?
Hepatitis C
189
What is Pitryiasis rosea?
"Herald patch" followed days later by "Christams tree" distribution. Multiple plaques w/ collarette scale.
190
What is the clinical courseof Pityriasis rosea?
Self resolving in 6-8 weeks
191
How does a sunburn occur?
UV irradiation causes DNA mut, inducing apoptosis of keratinocytes
192
Which UV irradiation is dominant in tanning & photoaging?
UVA
193
Which UV irradiation is involved in sunburns?
UVB
194
What can sunburns lead to?
Impetigo & skin cancers (basal cell CA, SCC & melanoma)
195
What is Impetigo?
Very superficial skin infection. Highly contagious
196
What causes Impetigo?
S. aureus or S. pyogenes
197
What does Impetigo look like?
Honey-colored crusting
198
What is Bullous impetigo?
hass bullae & is caused by *S. aureus*
199
What is Cellulitis?
Acute, painful, spreading infection of dermis & SQ tissues
200
What causes cellulitis
*S. pyogenes or S. aureus* of starts w/ a break in skin from trauma or another infection
201
What is Necrotizing fascitis?
Deeper tissue injury, usually from anaerobic bacteria or *S. pyogenes*. "Flesh-eating bacteria"
202
What does Necrotizing fasciitis cause?
Results in crepitus from methane & CO2 production. Causes bullae & a purple color to the skin
203
What is Staphylococcal scalded skin synd (SSSS)?
Exotoxin destroys keratinocyte attachments in stratum granulosum only
204
What is Staph scalded skin synd (SSSS) characterized by?
Fever & gen erythematous rash w/ sloughing of upper layers of the epidermis that heals completely
205
Who is SSSS seen in?
Newborns & children
206
What is hairy leukoplakia?
White painless plaques on the tongue that cannot be scraped off
207
What is hairy leukoplakia mediated by?
EBV
208
Who gets hairy leukoplakia?
HIV + pts
209
What is the MC skin cancer?
Basal cell CA
210
Where is Basal cell CA found?
Sun-exposed areas of body
211
What is the clinical course of Basal Cell CA?
locally invasive but almost never mets
212
What does Basal Cell CA look like?
Pink, pearly nodules\*, commonly w/ telangiectasias, rolled borders, & central crusting or ulceration. Also appear as nonhealing ulcers w/ infiltrating growth or as a scaling plaque (superficial BCC)
213
What is the histo of Basal Cell tumors?
Palisading peripheral nuclei\*
214
What is the 2nd MC skin cancer?
SCC
215
What is SCC assoc w/?
Excessive exposure to sunlight, immunosuppression, & occasionaly arsenic exposure
216
Where does SCC occur?
Appears on face, lower lip, ears & hands
217
What is the clincial course of SCC?
Locally invasive, but may spread to LN & will rarely mets. assoc w/ chronic draining sinuses
218
What do SCC lesions look like?
Ulcerative red lesions w/ freq scale
219
What is the histopathology of SCC?
keratin pearls
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What is Keratoacanthoma
Variant that grows rapidly (4-6 weeks) & may regress spon over months
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What is Melanoma?
Common tumor w/ significant risk of mets
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What is the tumor marker for Melanoma?
S-100
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What is melanoma assoc w/?
Sunlight exposure; fair-skinned persons are at high risk
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What does the depth of melanoma correlate w/?
risk of mets
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What are the **ABCDE**s of melanoma?
* **A**symmetry
* **B**order irreg
* **C**olor variation
* **D**iameter \>6mm
* **E**volution over time
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What mut is melanoma driven by?
Activating mut in BRAF kinase
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What is the 1º tx of melanoma?
Excision w/ appropriately wide margins
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What can pts w/ melanoma w/ BRAF V600E mut be tx w/?
May benefit from vemurafenib, a BRAF kinase inhibitor
