Musculoskeletal, Skin, & Connective Tissue Flashcards
(139 cards)
1
Q
Epidermis Layers
A
Surface to Base
- Stratum Corneum (keratin)
- Stratum Lucidum
- Stratum Granulosum
- Stratum Spinosum (spines = desmosomes)
- Stratum Basale (stem cell site)
2
Q
Sebaceous Gland
A
- Holocrine secretion of sebum
- Associated with hair follicle
3
Q
Eccrine Gland
A
- Secretes Sweat
- Found throughout body
4
Q
Apocrine Gland
A
- Secretes milky viscous fluid
- Found in axillae, genitalia, & areolae
- Does not become functional until puberty
- Malodorous b/c of bacterial action
5
Q
Epithelia Cell Junction: Tight Junction
A
(zonula occludens)
-prevents paracellular movement of solutes; composed of claudins & occludins
6
Q
Epithelia Cell Junction: Adherens Junction
A
(zonula adherens)
- below tight junction, forms “belt” connecting actin cytoskeletons of adjacent cells with CADherins (Ca2+ dependent adhesion proteins)
- loss of E-cadherin promotes metastasis
7
Q
Epithelia Cell Junction: Desmosome
A
(macula adherens)
- structural support via keratin interactions
- autoantibodies cause pemphigus vulgaris
8
Q
Epithelia Cell Junction: Gap Junction
A
-channel proteins called connexons permit electrical & chemical communications between cells
9
Q
Epithelia Cell Junction: Hemidesmosome
A
- connects keratin in basal cells to underlying basement membrane
- autoantibodies: bullous pemphigoid (hemidesmosomes are down “bullow”
10
Q
Epithelia Cell Junction: Integrins
A
-membrane proteins that maintain integrity of basement membrane by binding to laminin in BM
11
Q
Unhappy Triad/Knee Injury
A
- common injury in contact sports; lateral force applied to a planted leg
- triad includes tear of the ACL, MCL, & meniscus (classically medial, but lateral more common)
- Often requires surgical ACL reconstruction
- “anterior” and “posterior” in ACL & PCL refer to sites of tibial attachement
12
Q
Positive Anterior Drawer Sign
A
ACL tear
13
Q
Abnormal Passiv Abduction of knee?
A
MCL tear
14
Q
Where do you put pudendal nerve block to relieve pain of delivery?
A
Ischial spine
15
Q
Where is the appendix located?
A
2/3 of the way from the umbilicus to the anterior superior iliac spine (McBurney’s point)
16
Q
Where do you perform a lumbar puncture?
A
iliac crest
17
Q
Rotator Cuff Muscles
A
- Supraspinatus-abducts arm initially (before deltoid); most common rotator cuff injury
- Infraspinatus-laterally rotates arm; pitching injury
- Teres Minor-adducts and laterally rotates arm
- Subscapularis-medially rotates and adducts arm
-innervated by C5-C6
18
Q
Wrist Bones
A
-Scaphoid, Lunate, Triquestrum, Pisiform, Hamate, Capitate, Trapezoid, Trapezium
- Scaphoid is most commonly fractured carpal and is prone to avascular necrosis owing to retrograde blood supply
- Dislocation of lunate may cause acute carpal tunnel syndrome
19
Q
Carpal Tunnel Syndrome
A
-entrapment of median nerve in carpal tunnel; nerve compression leads to paresthesia, pain, and numbness in distribution of median nerve
20
Q
Axillary Nerve
A
(C5,C6)
Injury: fractured surgical neck of humerus, dislocation of humeral head
Motor Defect: Deltoid, arm abduction at shoulder
Sensory Deficit: over deltoid muscle
Sign: Atrophied deltoid
21
Q
Radial Nerve
A
(C5-T1)
Injury: Fracture at midshaft of humerus; “Saturday night palsy” (extended compression of axila by back of chair or crutches)
Motor Defect: BEST extensors: Brachioraadialis, Extensors of wrist and fingers, Supinator, Triceps
Sensory Deficit: Posterior arm & dorsal hand & thumb
Sign: Wrist Drop
22
Q
Median Nerve
A
(C5-C8,T1)
Injury: Fracture of supracondylar humerus (proximal lesion)
Motor Defect: Opposition of thumb, Lateral finger flexion, Wrist Flexion
Sensory Deficit: Dorsal & Palmar aspects of lateral 3.5 fingers, thenar eminence
Sign: “Ape Hand” “Pope’s Blessing”
23
Q
Ulnar Nerve
A
(C8,T1)
Injury: Fracture of medial epicondyle of humerus, “funny bone” (proximal lesion)
Motor Defect: Medial finger flexion, Wrist Flexion
Sensory Deficit: Medial 1.5 fingers, hypothenar eminence
Sign: Radial deviation of wrist upon wrist flexion
24
Q
Musculocutaneous Nerve
A
(C5-C7)
Injury: Upper trunk compression
Motor Defect: Biceps, brachialis, coracobrachialis, Flexion of arm at elbow
Sensory Deficit: Lateral forearm
25
Erb-Duchenne palsy
"waiter's tip"
- Traction of tear of the upper trunk of the brachial plexus (C5 & C6 roots); seen in infants following trauma during delivery
- Findings: limb hangs by side (paralysis of abductors), medially rotated (paralysis of lateral rotators), forearm is pronated (loss of biceps)
26
Klumpke's palsy & thoracic outlet syndrome
- An embryologic or childbirth defect affecting inferior trunk of brachial plexus (C8, T1); a cervical rib can compress subclavian artery & inferior trunk, resulting in throacic outlet syndrome
- atrophy of the thenar & hypothenar eminences
- atrophy of the interosseuous muscles
- sensory deficits on the medial side of the forearm & hand
- disappearance of the radial pulse upon moving the head toward the ipsilateral side
27
Distortions of the Hand
-"clawing" is easily conceptualized as loss of the lumbricals, which flex the MCP joints and extend both the DIP and PIP joints
28
Ulnar Claw
- Can be caused by long-standing injury to ulnar nerve at hamate (by falling into outstretched hand)
- Distal ulnar nerve lesion leads to loss of medial lumbrical function which lead to inability to extend 4th & 5th digits "clawing" when trying to open the hand
29
Median Claw
- Can be caused by carpal tunnel syndrome of dislocated lunate
- Distal median nerve lesion (after branch containing C5-C7 branches off to feed forearm flexors) leads to loss of lateral lumbrical function; 2nd and 3rd digits are clawed upon attempted finger extension
30
"Pope's Blessing"
- Proximal median nerve lesion causes loss of lateral finger flexion & thumb opposition
- When asked to make fist, 2nd and 3rd digits remain extended & thumb remains unopposed, which looks like the hand of benediction
31
"Ape Hand"
-Proximal median nerve lesion leads to loss of opponens pollicis muscle function which causes unopposable thumb (inability to abduct thumb)
32
Klumpke's total claw
-Lesion of lower trunk (C8, T1) of brachial plexus leads to loss of function of all lumbricals; forearm finger flexors (fed by part of median nerve with C5-C7) and finger extensors (fed by redial nerve) are unopposed leading to clawing of all digits
33
Long Thoracic Nerve
Serratus anterior - anchors scapula to thoracic cage
- used for abduction above horizontal position
- can be injured in mastectomy (winged scapula & ipsilateral lymphedema
34
Thenar
(median)
- Opponens pollicis, Abductor pollicis brevis, Flexor policis brevis
- oppose, abduct, flex
35
Hypothenar
(ulnar)
- Opponens digiti minimi, Abductor digiti minimi, Flexor digiti minimi
- oppose, abduct, flex
36
Dorsal Interosseous Muscles
abduct the fingers
37
Palmar Interosseous Muscles
adduct the fingers
38
Lumbrical Muscles
flex at the MCP joint, extend PIP & DIP joints
39
Obturator Nerve
(L2-L4)
Injury: Anterior hip dislocation
Motor Deficit: Thigh Adduction
Sensory Deficit: Medial Thigh
40
Femoral Nerve
(L2-L4)
Injury: Pelvic Fracture
Motor Deficit: Thigh flexion and leg extension
Sensory Deficit: Anterior thigh & medial leg
41
Common Peroneal Nerve
(L4-S2)
Injury: Trauma or compression of lateral aspect of leg or fibula neck fracture
Motor Deficit: Foot eversion & dorsiflexion; toe extension; foot drop, foot slap, steppage gait
Sensory Deficit: Anterolateral leg & dorsal aspect of foot
PED = Peroneal Everts & Dorsiflexes (foot drop)
42
Tibial Nerve
(L4-S3)
Injury: Knee trauma
Motor Deficit: Foot inversion & plantarflexion; toe flexion
Sensory Deficit: Sole of foot
TIP = Tibial Inverts & Plantarflexes (can't stand on tiptoes if injured)
43
Superior Gluteal Nerve
(L4-S1)
Injury: Posterior hip dislocation or polio
Motor Deficit: THigh abduction (+ Trendelenburg sign-contralateral hip drop when standing on leg ipsilateral to site of lesion)
44
Inferior Gluteal Nerve
(L5-S2)
Injury: Posterior hip dislocation
Motor Deficit: Can't jump, climb stairs, or rise from seated position; can't push inferiorly (downward)
45
Sciatic Nerve
(L4-S3)
| -posterior thigh, splits into common peroneal & tibial nerve
46
Muscle Contraction
1. Action Potential depolarization opens presynaptic voltage-gated Ca2+ channels, inducing neurotransmitter release
2. Postsynaptic ligand binding leads to muscle cell depolarization in motor end plate
3. Depolarization travels along muscle cell & down T-tubule
4. Depolarization of the voltage-sensitive dihydropyridine receptor, mechanically coupled to the ryanodine receptor on the sarcoplasmic reticulum, induces a conformational change causing Ca2+ release from the SR
5. Released Ca2+ binds to troponin C, causing a conformational change that moves tropomyosin out of the myosin-binding groove on actin filaments
6. Myosin releases bound ADP & is displaced on the actin filament (power stroke), contraction results in shortening of H & I bands and b/w Z lines (HIZ shrinkage), but the A band remains the same length
47
Type 1 Muscle Fibers
- Slow twitch, red fibers resulting from inc. mytochondria & myoglobin concentration (inc. oxidative phosphorylation) leads to sustained contraction
- 1 slow red ox
48
Type 2 Muscle Fibers
-Fast twitch, white fibers resulting from dec. mitochondrial & myoglobin concentration (inc. anaerobic glycolysis); weight training results in hypertrophy of fast-twitch muscle fibers
49
Bone Formation: Endochondral Ossification
- Bones of axial & appendicular skeleton, and base of the skull
- Cartilaginous model of bone is first made by chondrocytes
- Osteoclasts & osteoblasts later replace with woven bone & then remodel to lamellar bone
- In adults, woven bone occurs after fractures and in Paget's disease
50
Membranous Ossification
- Bones of calvarium & facial bones
- Woven bone formed directly without cartilage
- Later remodeled to lamellar bone
51
Osteoblasts
Build bone by secreting collagen & catalyzing mineralization
-Differentiate from mesenchymal stem cells in periosteum
52
Osteoclasts
- Multinucleated cells that dissolve bone by secreting acid and collagenases
- Differentiate from monocytes/macrophages
53
Parathyroid Hormone
- At low, intermittent levels, exerts anabolic effects (building bone) on osteoblasts and osteoclasts (indirect)
- Chronic high PTH levels (primary hyperparathyroidism) cause catabolic effects (osteitis fibrosa cystica)
54
Estrogen
- Inhibits apoptosis in bone-forming osteoblasts & induces apoptosis in bone-resorbing osteoclasts
- under estrogen deficiency (surgical or postmenopausal), excess remodeling cycles & bone resorption lead to osteoporosis
55
Achondroplasia
- Failure of longitudinal bone growth (endochondral ossification), short limbs
- Membranous ossification is not affected, large head relative to limbs
- Constitutive activation of fibroblast growth factor receptor (FGFR3) actually inhibits chondrocyte proliferation > 85% of mutations occur sporadically are associated with advanced paternal age, but the condition also demonstrates autosomal-dominant inheritance
- common cause of dwarfism
- normal life span and fertility
56
Osteoporosis
- Trabecular (spongy) bone loses mass and interconnections despite normal bone mineralization & lab values (serum Ca2+ and PO4-)
- Can lead to vertebral crush fractures: acute back pain, loss of height, kyphosis
57
Osteoporosis: Type I
- Postmenopausal, inc. bone resorption due to dec. estrogen levels
- Femoral neck fracture, distal radius (Colle's) fractures
58
Osteoporosis: Type II
- Senile osteoporosis: affects men and women > 70 yrs of age
- Prophylaxis: regular weight-bearing exercise & adequate Ca and Vit D intake throughout adulthood
- Treatment: estrogen (SERMs) and/or calcitonin; bisphosphonates or pulsatile PTH for severe cases. Glucocorticoids are contraindicated
59
Osteopetrosis
"marble bone disease"
- Failure of normal bone resorption due to defective osteoclasts, thickened, dense bones that are prone to fracture. Bone fills marrow space, causing pancytopenia, extramedullary hematopoiesis.
- Mutations (carbonic anhydrase II) impair ability of osteoclast to generate acidic env. necessary for bone resorption. X-ray show bone-in-bone appearance.
- Can result in cranial nerve impingement and palsies as a result of narrowed foramina
- Bone marrow transplant is potentially curative as osteoclasts are derived from monocytes
60
Osteomalacia/Rickets
rickets - kids, osteomalacia - adults
- Vit. D deficiency, due to defective mineralization/calcification of osteoid, soft bones that bow out
- Dec. vit D, dec. serum Ca, inc. PTH secretion, dec. serum phosphate
- hyperactivity of osteoblasts, inc. alkaline phos. (osteoblasts require alkaline environment)
61
Paget's Disease of Bone
| osteitis deformans
- Common, localized disorder of bone remodeling caused by inc. in both osteoblastic & osteoclastic activity
- Serum Ca, phosphorus, PTH levels are normal
- Inc. ALP
- Mosaic "woven" bone pattern, long bone chalk-stick fractures, inc. blood flow from inc. arteriovenous shunts may cause high-output heart failure
- inc. risk of osteogenic sarcoma
- Hat size inc.. hearing loss common due to auditory foramen narrowing
62
Polyostotic Fibrous Dysplasia
- Bone is replaced by fibroblasts, collagen, and irregular bony trabeculae
- McCune-Albright syndrome is a form of polyostotic fibrous dysplasia characterized by multiple unilateral bone lesions associated with endocrine abnormalities (precocious puberty) and cafe-au-lait spots
63
Primary Bone Tumors: Giant Cell Tumor (osteoclastoma)
- benign tumors
- 20-40 yrs of age
- epiphyseal end of long bones
- locally aggressive benign tumor often around the distal femur, proximal tibial region (knee)
- "Double bubble" or "soap bubble" appearance on x-ray
- Spindle-shaped cells with multinucleated giant cells
64
Primary Bone Tumors: Osteochondroma (exostosis)
- most common benign tumor
- males <25 yrs of age
- mature bone with cartilaginous cap, commonly originates from long metaphysis
- malignant transformation to chondrosarcoma is rare
65
Primary Bone Tumors: Osteosarcoma (osteogenic sarcoma)
- 2nd most common primary malignant bone tumor (after multiple myeloma)
- Male>female, 10-20 yrs of age (primary)
- Predisposing factors: Paget's disease of bone, bone infarcts, radiation, familial retinoblastoma
- Metaphysis of long bones, often around distal femur, proximal tibial region (knee)
- Codman's triangle (from elevation of periosteum) or sunburst pattern on x-ray
- aggressive. Treat with surgical en bloc resection (with limb salvage) & chemotherapy
66
Primary Bone Tumors: Ewing's Sarcoma
Malignant Tumors
- Boys < 15 yrs of age
- commonly appears in diaphysis of long bones, pelvis, scapula, & ribs
- Anaplastic small blue cell malignant tumor
- Extremely aggressive with early metastases, but responsive to chemo
- "Onion skin" appearance in bone ("going out for Ewings and onion rings")
- Associated with t(11;22) translocation
67
Primary Bone Tumors: Chondrosarcoma
Malignant Tumors
- men 30-60 yrs of age, usually located in pelvis, spine, scapula, humerus, tibia, or femur
- malignant cartilaginous tumor
- may be of primary origin or from osteochondroma
- expansile glistening mass within the medullary cavity
68
Osteoarthritis
-Mechanical-joint wear and tear destroys articular cartilage
-Subchondral cysts, sclerosis, osteophytes (bone spurs), eburnation (polished, ivory-like appearance of bone), Heberden's nodes (DIP), and Bouchard's nodes (PIP), no MCP involvement
-age, obesity, joint deformity
-pain in weight-bearing joints after use (at the end of the day), improving with rest
-Knee cartilage loss begins medially "bowlegged"
-noninflammatory, no systemic symptoms
Treat: NSAIDs, intra-articular glucocorticoids
69
Rheumatoid Arthritis
- Autoimmune-inflammatory destruction of synovial joints, Type III hypersensitivity
- Pannus formation in joints (MCP, PIP), subcutaneous rheumatoid nodules (fibrinoid necrosis), ulnar deviation of fingers, subluxation, Baker's cyst (in popliteal fossa), no DIP involvement
- Females>males, 80% have +Rh factor (anti-IgG); anti-cyclic citrullinated peptide ab is more specific
- Strong association with HLA-DR4
- Morning stiffness lasting >30 min. & improving with use, symmetric joints involvement, systemic symptoms (fever, fatigue, pleuritis, pericarditis)
- Treatment: NSAIDs, glucocorticoids, disease-modifying agents (methotrexate, sulfasalazine, TNF-alpha, inhibitors)
70
Sjogren's Syndrome
- Lymphocytic infiltration of exocrine glands, especially lacrimal & salivary
- Classic Triad: Xerophthalmia (dry eyes, conjunctivitis, "sand in eyes"), Xerostomia (dry mouth, dysphagia), Arthritis
- Parotid enlargement, inc. risk of B-cell lymphoma, dental caries. Autoantibodies to ribonucleoprotein antigens: SS-A (Ro), SS-B (La)
- Predominantly affects females b/w 40 & 60 years of age
- associated with rheumatoid arthritis
71
Findings in Gout
- Precipitation of monosodium urate crystals into joints due to hyperuricemia, which can be caused by Lesch-Nyhan syndrome, PRPP excess, dec. excretion of uric acid (thiazide diuretics), inc. cell turnover, or von Gierke's disease
- 90% due to underexcretion; 10% due to overproduction
- Crystals are needle shaped & negatively birefringent = yellow crystals under parallel light
- more common in men
72
Symptoms in Gout
- Asymmetric joint distribution
- Joint is swollen, red, painful
- Classic: 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 kidneys as uric acid, causing dec. uric acid secretion & subsequent buildup in blood)
73
Treatment of Gout
Acute: NSAIDs (indomethacin), glucocorticoids
Chronic: Xanthine oxidase inhibitors (allopurinol, febuxostat)
74
Pseudogout
- Caused by deposition of Ca pyrophosphate crystals within the joint space
- Forms basophilic, rhomboid crystals that are weakly positively birefringent
- Usually affects large joints (classically the knee)
- >50 yrs old; both sexes affected equally
- Treatment: NSAIDs for sudden, severe attacks; steroids, & colchicine
- Blue when parallel to the light
75
Infectious Arthritis
- S. aureus, Streptococcus, & Neisseria gonorrhoeae are common causes
- Gonococcal arthritis is an STD that presents as a migratory arthritis with an asymmetric pattern
- Affected joint is swollen, red, painful
- STD = Synovitis (knee), Tenosynovitis (hand) & Dermatitis (pustules)
76
Osteonecrosis (avascular necrosis)
- Infarction of bone marrow
- Pain associated with activity, caused by trauma, high-dose corticosteroids, alcoholism, sickle cell
- most common site is femoral head
77
Seronegative Spondyloarthropathies
- Arthritis without rheumatoid factor (no anti-IgG ab)
- Strong association with HLA-B27 (gene that codes for HLA MHC class I)
- Occurs more often in males
78
Psoriatic Arthritis
Seronegative Spondyloarthropathies
- Joint pain & stiffness associated with psoriasis
- Asymmetric & patchy involvement
- Dactylitis "sausage fingers", "pencil-in-cup" deformity on x-ray
- seen in fewer than 1/3 of patients with psoriasis
79
Ankylosing Spondylitis
Seronegative Spondyloarthropathies
-Chronic inflammatory disease of spine & sacroiliac joints, ankylosis (stiff spine due to fusion of joints), uveitis, & aortic regurgitation
80
Inflammatory Bowel Disease
Seronegative Spondyloarthropathies
| -Crohn's disease & ulcerative colitis are often accompanied by anklyosing spondylitis or peripheral arthritis
81
Reactive Arthritis (Reiter's Syndrome)
Classic Triad: Conjunctivitis (and anterior uveitis), Urethritis, Arthritis
"Can't see, can't pee, can't climb a tree"
-Post-GI or chlamydia infections
82
Systemic Lupus Erythematosus
-90% female & b/w 14-45
-most common & severe in black females
-Presentation: fever, fatigue, weight loss, Libman-Sacks endocarditis (verrucous, wart-like, sterile vegetations on both sides of valve), hilar adenopathy, and Raynaud's phenomenon
-Nephritis is common cause of death in SLE (diffuse proliferative glomerulonephritis if nephritis & membranous glomerulonephritis if nephrotic)
-False + on syphilis test (RPR/VDRL) due to antiphospholipid ab, which cross-react cardiolipin used in tests
Labs: +ANA (sensitive, but not specific)
+anti-dsDNA (very specific, poor prognosis)
+anti-SM (very specific, not prognostic)
+antihistone ab (more sensitive for drug-induced lupus
Immunoglobuins, Malar rash, Discoid rash, Antinuclear Ab, Mucositis (oropharyngeal ulcers), Neurologic disorders, Serositis (pleuritis, pericarditis), Hematologic disorders, Arthritis, Renal Disorders, Photosensitivity (I'M DAMN SHARP)
83
Sarcoidosis
-immune-mediated, widespread noncaseating granulomas & elevated serum ACE levels
-black females
-often asymptomatic except for enlarged lymph node, incidental findings on CXR of bilateral hilar adenopathy or reticular opacities
-associated with restrictive lung disease (interstitial fibrosis), erythema nodosum, Bell's palsy, epithelial granulomas containing microscopic Schaumann & asteroid bodies, uveitis, & hypercalcemia (due to elevated 1alpha-hydroxylase-mediated vit D activation in epithelioid macrophages)
Treatment: steroids
84
Polymyalgia Rheumatica
Symptoms: pain & stiffness in shoulders & hips, often with fever, malaise, weight loss, does not cause muscular weakness
-more common in women >50 yrs, associated with temporal (giant cell) arteritis
Findings: inc. ESR, normal CK
Treatment: Rapid response to low-dose corticosteroids
85
Fibromyalgia
- most commonly seen in women 20-50 yrs.
| - Chronic, widespread musculoskeletal pain associated with stiffness, parasthesia, poor sleep, & fatigue
86
Polymyositis
-progressive symmetric proximal muscle weakness, characterized by endomysial inflammation with CD8+ T cells
-most often involves shoulders
Findings: inc. CK, positive ANA, + anti-Jo-1 ab
Treatment: steroids
87
Dermatomyositis
-similar to polymyositis, but also involves malar rash (similar to SLE)
-Gottron's papules, heliotrope rash, "shawl & face" rash, "mechanic's hands"
-inc. risk of occult malignancy
-perimysial inflammation & atrophy with CD4+ T-cells
Findings: inc. CK, positive ANA, + anti-Jo-1 ab
Treatment: steroids
88
Myasthenia Gravis
- most common neuromuscular junction disease
- autoabs to postsynaptic ACh receptor
- Ptosis, diplopia, weakness, Worsens with muscle use
- Associated with Thymoma, thymic hyperplasia
- Give AChE inhibitor to reverse symptoms
89
Lambert-Eaton Myastheniac Syndrome
- uncommon neuromuscular junction disease
- autoabs to presynaptic Ca2+ channel, dec. ACh release
- proximal muscle weakness, improves with muscle use
- associated with small cell lung cancer
- no effect with AChE inhibitor administration
90
Myositis Ossificans
- Metaplasia of skeletal muscle to bone following muscular trauma
- Most often seen in upper or lower extremity
- May present as suspicious "mass" at site of known trauma or as incidental finding on radiography
91
Scleroderma (systemic sclerosis)
- Excessive fibrosis & collagen deposition throughout the body
- Commonly sclerosis of skin, manifesting as puffy & taut skin with absence of wrinkles
- Also sclerosis of renal, pulmonary (most likely cause of death), cardiovascular, & GI systems
- 75% female
- Diffuse Scleroderma
- CREST Syndrome
92
Diffuse Scleroderma
- widespread skin involvement, rapid progression, early visceral involvement
- Associated with anti-Scl-70 ab (anti-DNA topo 1 antibody)
93
CREST Syndrome
- Calcinosis
- Raynaud's phenomenon
- Esophageal dysmotility
- Sclerodactyly
- Telangiectasis
- Limited skin involvement , often confined to fingers & face, more benign clinical course
- Associated with anti-Centromere antibody
94
Macule
- Flat lesion with well-circuscribed change in skin color < 5mm
- Freckle, labile macule
95
Patch
- Macule > 5mm
| - Large birthmark (congenital nevus)
96
Papule
- Elevated solid skin lesion < 5mm
| - Mole (nevus), acne
97
Plaque
Papule > 5mm
| -psoriasis
98
Vesicle
Small fluid-containing blister < 5mm
| -chickenpox (varicella), shingles (zoster)
99
Bulla
Large fluid-containing blister > 5mm
| -Bullous pemphigoid
100
Pustule
Vesicle containing pus
| -Pustular psoriasis
101
Wheal
Transient smooth papule or plaque
| -Hives (urticaria)
102
Scale
Flaking off of stratum corneum
| -Eczema, psoriasis, SCC
103
Crust
Dry exudate
| -impetigo
104
Hyperkeratosis
inc. thickness of stratum corneum (psoriasis)
105
Parakeratosis
hyperkeratosis with retention of nuclei in stratum corneum (psoriasis)
106
Acantholysis
Separation of epidermal cells (pemphigus vulgaris)
107
Acanthosis
```
Epidermal hyperplasia (inc. spinosum)
(Acanthosis nigricans)
```
108
Dermatitis
Inflammation of the skin (atopic dermatitis)
109
Albinism
Pigmented Skin Disorders
- Normal melanocyte # with dec. melanin production due to dec. tyrosinase activity
- Can also be caused by failure of neural crest cell migration during development
110
Melasma (chloasma)
Pigmented Skin Disorders
| -Hyperpigmentation associated with pregnancy "mask of pregnancy" or OCP use
111
Vitiligo
Pigmented Skin Disorders
- Irregular areas of complete depigmentation
- Caused by a dec. in melanocytes
112
Verrucae
- Warts; caused by HPV
- Soft, tan-colored, cauliflower-like papules
- Epidermal hyperplasia, hyperkeratosis, koilocytosis
- Condyloma acuminatum on genitals
113
Melanocytic Nevus
- Common mole
- Benign, but melanoma can arise in congenital or atypical moles
- Intradermal nevi are papular
- Junctional nevi are flat macules
114
Urticaria
- Hives
| - Pruritic wheals that form after mast cell degranulation
115
Ephelis
- Freckle
| - Normal # of melanocytes, inc. melanin pigment
116
Atopic Dermatitis (Eczema)
- Pruritic eruption, commonly on skin flexures
- Often associated with other atopic diseases (asthma, allergic rhinitis)
- Usually starts on the face in infancy & often appears in the antecubital fossae thereafter
117
Allergic Contact Dermatitis
- Type IV hypersensitivity rxn that follows exposure to allergen
- Lesions occur at site of contact (nickel, poison ivy, neomycin)
118
Psoriasis
- Papules & plaques with silvery scaling, especially on knees & elbows
- Acanthosis with parakeratotic scaling (nuclei still in stratum corneum)
- Inc. stratum spinosum, dec. stratum granulosum
- Auspitz sign - pinpoint bleeding spots from exposure of dermal papillae when scales are scraped off
- Can be associated with nail pitting & psoriatic arthritis
119
Seborrheic Keratosis
- Flat, greasy, pigmented squamous epithelial proliferation with keratin-filled cysts (horn cysts)
- Looks "stuck on"
- Lesions occur on head, trunk, & extremities
- Common benign neoplasm of older persons
- Leser-Trelat sign: sudden appearance of multiple seborrheic keratosis, indicating on underlying malignancy (GI, lymphoid)
120
Pemphigus Vulgaris
Blistering Skin Disorders
- Potentially fatal autoimmune skin disorder with IgG ab against desmoglein 3 (1 &/or 3), a part of desmosomes (needed for cell adhesion)
- Immunofluorescence reveals abs around epidermal cells in a reticular or netlike pattern
- Acantholysis-intraepidermal bullae causing flaccid blister involving the skin & oral mucosa
- + Nikolsky's sign (separation of epidermis upon manual stroking of skin)
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Bullous Pemphigoid
Blistering Skin Disorders
- Autoimmune disorder with IgG ab against hemidesmosomes (epidermal basement membrane, abs are "bullow" the epidermis), shows linear immunofluorescence
- Eosinophils within tense blisters
- Similar to but less severe than pemphigus vulgaris , affects skin but spares orla mucosa
- Negative Nikolsky's sign
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Dermatitis Herpetiformis
Blistering Skin Disorders
- Pruritic papules, vesicles, & bullae
- Deposits of IgA at the tips of dermal papillae
- Associated with celiac disease
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Erythema Multiforme
Blistering Skin Disorders
- Associated with infections (Mycoplasma pneumoniae, HSV), drugs (sulfa drugs, beta-lactams, phenytoin), cancers, & autoimmune disease
- Presents with multiple types of lesions (macules, papules, vesicles, target lesions-look like targets with multiple rings and a dusky center showing epithelial distuption)
124
Stevens-Johnson Syndrome
Blistering Skin Disorders
- fever, bulla formation, & necrosis, sloughing of skin, & a high mortality rate
- Typically 2 mucus membranes are involved & skin lesion may appear like targets as seen in erythema multiforme
- a more severe form with > 30% of the body surface area involved is toxic epidermal necrolysis
125
Acanthosis Nigricans
- Epidermal hyperplasia causing symmetrical, hyperpigmented, velvety thickening of skin, especially on neck or in axilla
- Associated with hyperinsulinemia (diabetes, obesity, Cushing's syndrome) & visceral malignancy
126
Actinic Keratosis
- Premalignant lesions caused by sun exposure
- Small, rough, erythematous or brownish papules or plaques
- Risk of squamous cell carcinoma is proportional to degree of epithelial dysplasia
127
Erythema Nodosum
- Inflammatory lesions of subcutaneous fat, usually on anterior shins
- Associated with sarcoidosis, coccidioidomycosis, histoplasmosis, TB, streptococcal infections, leprosy, & Crohn's disease
128
Lichen Planus
Pruritic, Purple, Polygonal Planar Papules an dPlaques are the 6 P's of lichen planus
- Sawtooth infiltrate of lymphocytes at dermal-epidermal junction
- Associated with hep C
129
Pityriasis Rosea
"Herald patch" followed days later by "Christmas tree" distribution
- Multiple plaques with collarette scale
- Self-resolving in 6-8 weeks
130
Sunburn
UV irradiation causes DNA mutations, inducing apoptosis of keratinocytes
- UVA is dominant in tanning and photoaging, UVB in sunburn
- Can lead to impetigo and skin cancers (basal cell carcinoma, squamous cel carcinoma, & melanoma)
131
Impetigo
- Very superficial skin infection
- Usually from S. aureus or S. pyogenes
- Highly contagious
- Honey-colored crusting
- Bullous impetigo has bullae & is usually caused by S. aureus
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Cellulitis
- Acute, painful, spreading infection of dermis & subcutaneous tissues
- Usually form S. pyogenes or S. aureus
- Often starts with a break in skin from trauma or another infection
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Necrotizing Fasciitis
- Deeper tissue injury, usually from anarobic bacterial or S. pyogenes
- Results in crepitus from methane & CO2 production
- "Flesh-eating" bacteria
- Causes bullae & a purple color to the skin
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Staphylococcal Scaled Skin Syndrome (SSSS)
- Exotoxin destroys keratinocyte attachment in the stratum granulosum only (vs. toxic epidermal necrolysis, which destroys the epidermal-dermal junction)
- fever & generalized erythematous rash with sloughing of the upper layers of the epidermis that heals completely
- Seen in newborns & children
135
Hairy Leukoplakia
- White, painless plaques on the tongue that can't be scraped off
- EBV mediated
- Occurs in HIV+ patients
136
Skin Cancer: Basal Cell Carcinoma:
- most common
- found in sun-exposed areas of body
- locally invasive, but almost never metastasizes
- Pink, pearly nodules, commonly with telangiectasias, rolled borders, & central crusting or ulceration
- BCCs also appear as nonhealing ulcers with infiltrating growth or as a scaling plaque (superficial BCC)
- "palisading" nuclei
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Skin Cancer: Squamous Cell Carcinoma
- second most common skin cancer
- associated with excessive exposure to sunlight, immunosuppression, & occasionally arsenic exposure
- commonly appears on face, lower lip, ears, & hands
- locally invasive, but may spread to lymph nodes & will rarely metastasize
- Ulcerative red lesions with frequent scale
- Associated with chronic draining sinuses
- Histopathology: keratin "pearls"
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Keratonacanthoma
-a varient of squamous cell carcinoma of the skin that grows rapidly (4-6 weeks) and may regress spontaneously over months
139
Skin Cancer: Melanoma
- common tumor with significant risk of metastasis
- S-100 tumor marker
- Associated with sunlight exposure; fair-skinned persons are at inc. risk
- Depth of tumor correlates with risk of metastasis
- Look for ABCDE: Asymmetry, Border irregularity, Color variation, Diameter (>6mm), Evolution over time
- At least 4 diff. types
- often driven by activation mutation in BRAF kinase
- Primary treatment is excision with appropriately wide margins
- Metastatic or unresectable melanoma in patients with BRAF V600E mutation may benefit from vemurafenif, a BRAF kinase inhibitor
