Musculoskeletal Flashcards
(446 cards)
1
Q
What is the mutation seen in achondroplasia and what is its inheritance pattern?
A
Activating mutation in fibroblast growth factor receptor 3 (FGFR3), it is autosomal dominant. Gain of function mutation inhibits growth of cartilage and long bones.
2
Q
What are the clinical features of achondroplasia?
A
Short extremities with normal sized head and chest. (Due to loss of endochondral long bone formation)
3
Q
Why is the sclera blue in osteogenesis imperfecta?
A
Exposure of the choroidal veins because of thin sclera, which contains type I collagen.
4
Q
Which type of collagen is defective in osteogenesis imperfecta?
A
Type I (collagen in bone - Autosomal dominant)
5
Q
Which cells are dysfunctional in osteopetrosis?
A
Osteoclasts (can’t resorb bone)
6
Q
What is the most common enzyme mutation resulting in osteopetrosis and why does it cause the disease?
A
Carbonic anhydrase II mutations result in osteopetrosis because the enzyme is normally used to produce H+ ions which allow for the breakdown of bone and resorption of calcium by osteoclasts. Without it, bone can’t be broken down.
7
Q
What will be seen on X-ray of a patient with osteopetrosis?
A
Very thick bone with no medulla (bone-in-bone appearance)
8
Q
Why do patients with osteopetrosis commonly have renal tubular acidosis?
A
Because the most common mutation seen in osteopetrosis is carbonic anhydrase, which, when lost, also causes RTA.
9
Q
What is the treatment for osteopetrosis?
A
Bone marrow transplant (get new monocytes, which eventually become osteoclasts).
10
Q
What is the pathophysiology of rickets/osteomalacia?
A
Defective mineralization of osteoid due to vitamin D deficiency. Results in deposition of osteoid throughout the body.
11
Q
What enzyme is a marker for osteoblast activity?
A
Alkaline phosphatase (alkaline environment needed to lay down calcium in bone)
12
Q
Why are postmenopausal women at higher risk for osteoporosis?
A
Estrogen levels decline. Estrogen is protective of bone mass.
13
Q
Describe the changes seen in serum calcium, phosphate, PTH, and alkaline phosphate seen in a woman with severe osteoporosis.
A
All will be normal!
14
Q
Which type of bone is lost in osteoporosis?
A
Trabecular (spongy) bone
15
Q
What are the two types of osteoporosis?
A
Postmenopausal (due to loss of estrogen) Senile (loss of bone density with age)
16
Q
Explain how PTH works on bone.
A
PTH activates osteoblasts, which activate the osteoclasts to resorb bone.
17
Q
Explain the pathophysiology of Paget’s disease of bone.
A
Increase in osteoclast activity results in increase in osteoblast activity. Osteoclast burns out before the osteoblast, and the osteoblast lays down as much bone as possible, in a mosaic fashion. Results in a thick, sclerotic bone that fractures easily.
18
Q
Is Paget’s disease diffuse or localized?
A
Localized - it does not affect the entire skeleton.
19
Q
Isolated elevated alkaline phosphatase is seen with what disease?
A
Paget’s disease of bone (calcium, phosphorous, PTH normal)
20
Q
What are the two main complications of Paget’s disease of bone?
A
High output cardiac failure (due to AV shunts) Osteosarcoma (malignant tumor of osteoblasts)
21
Q
Where in the bone is osteomyelitis seen in kids?
A
Metaphysis (highly vascularized)
22
Q
Where in the bone is osteomyelitis seen in adults?
A
Epiphysis
23
Q
What is the #1 overall cause of osteomyelitis?
A
S. aureus
24
Q
What is the #1 cause of osteomyelitis in sickle cell disease?
A
Salmonella
25
What is the #1 cause of osteomyelitis in an IVDU or patient with diabetes?
Pseudomonas
26
What causes osteomyelitis in a patient that has been bitten by a dog or cat?
Pasturella
27
What will be seen on x-ray in a patient with osteomyelitis?
Lytic focus surrounded by sclerosis
28
Where are osteomas most commonly located?
Facial bones
29
What is the triad seen with Gardner syndrome?
Familial adenomous polyposis (colon polyps), retroperitoneal fibromatosis, facial bone osteomas.
30
What is an osteoid osteoma?
Benign tumor of osteoblasts surrounded by rim of reactive bone seen in diaphysis of long bones. It causes bone pain that responds to aspirin.
31
What is significant about the pain in an osteoid osteoma?
It resolves with aspirin
32
What will be seen on x-ray in an osteoid osteoma?
Bony mass with radiolucent core (center core of osteoid that is surrounded by reactive bone).
33
What is the most common benign tumor of bone?
Osteochondroma (mature bone with a cartilagenous cap)
34
What is significant about the pain in an osteoblastoma?
It does NOT respond to aspirin (osteoid osteoma pain responds to aspirin)
35
What are the two benign tumors of osteoblasts and how are they differentiated?
Osteoid osteoma (small, arises in diaphyses, pain resolves with ASA) Osteoblastoma (large, arises in vertebrae, pain does not resolve with ASA)
36
Describe the morphology of an osteochondroma.
A benign tumor of bone with an overlying cartilage cap. Arises from a lateral projection of growth plate.
37
An osteochondroma can transform into which malignancy?
Chondrosarcoma
38
Osteosarcoma is a malignancy of which type of cells?
Osteoblasts
39
In which two age groups is osteosarcoma seen?
Teens and elderly.
40
Mutation of which tumor suppressor gene increases risk for osteosarcoma?
Rb
41
What are two predisposing factors to osteosarcoma in the elderly?
Radiation, Paget's disease of the bone.
42
Where do osteosarcomas most commonly arise?
Metaphysis of long bones
43
What is Codman's angle?
Elevation of the periosteum seen with rapidly growing osteosarcoma invading the surrounding soft tissue.
44
What is the hallmark of biopsy in osteosarcoma?
Pleiomorphic cells producing pink osteoid
45
Giant cell tumors (osteoclastoma) arise in which part of the bone?
Epiphysis (only tumor that arises in the epiphysis!)
46
What is the only tumor that arises in the epiphysis?
Giant cell tumor (osteoclastoma)
47
What is the "soap bubble" sign and what is it associated with?
Appearance of dark spots in the epiphysis due to reactive bone formation in a giant cell tumor (osteoclastoma).
48
Ewing sarcoma is derived from...
Neuroectoderm
49
Where does Ewing sarcoma arise in the bone?
Diaphysis (grows in medullary cavity)
50
What is seen on x-ray in Ewing sarcoma?
Onion skin appearance due to laying down of new periosteum.
51
What is seen on biopsy of Ewing sarcoma?
Small round blue cells
52
What is the translocation seen in Ewing sarcoma?
t(11;22) (11 + 22 = 33, Patrick Ewing's number)
53
Where do chondromas typically arise?
Small bones of hands and feet (in the medulla)
54
Where do chondrosarcomas typically arise?
The medulla of the pelvis or central skeleton
55
Tumors that metastasize to the bone typically form which type of lesions?
Osteolytic (punched out)
56
What type of lesions do prostate cancer metastases produce in the bone?
Osteoblastic lesions - get sclerosis of the bone due to laying down of new bone (exception to the rule - normally mets give osteolytic lesions).
57
Cartilage contains which type of collagen?
Type II
58
Osteoarthritis (DJD) typically occurs in which joints?
Hip, lumbar spine, knees, DIP/PIP of fingers.
59
Joint stiffness in the morning that worsens during the day is typical of which arthropathy?
Osteoarthritis (DJD)
60
What is the pathologic hallmark of osteoarthritis (DJD)?
Disruption of the cartilage that lines the articular surface with osteophyte formation.
61
Where are Heberden and Bouchard's nodes located?
Bouchard's - PIP; Heberden's - DIP; (Bros before Hoes)
62
Which HLA is RA associated with?
HLA-DR4 (R4 sorta looks like RA)
63
HLA DR 4 increases the risk for...
RA
64
What is the pathological hallmark of RA?
Inflammation of the synovium leading to formation of pannus (inflamed granulation tissue)
65
What is pannus?
An abnormal layer of inflamed granulation tissue, which is hallmark for RA.
66
Joint stiffness in the morning that improves with activity during the day is typical of which arthropathy?
RA
67
Which joint is spared in RA?
DIP (it is involved in OA- important distinction!)
68
What type of hypersensitivity is RA?
Type III
69
What causes joint deformity (ulnar deviation of fingers) in RA?
Myofibroblasts in granulation tissue (pannus) contract and pull the joint.
70
What is rheumatoid factor?
IgM autoantibody against Fc portion of IgG
71
Which joints are most commonly involved in ankylosing spondylitis?
SI joints and spine
72
Aortic regurgitation is associated with which arthropathy?
Ankylosing spondylitis (AR secondary to aortitis)
73
Ankylosing spondylitis is associated with what HLA marker?
HLA B-27
74
What is the classic triad seen in reactive arthritis (Reiter syndrome)?
Uveitis, urethritis, arthritis.
75
Reactive arthritis (Reiter syndrome) typically occurs after infection with...
Chlamydia or GI bugs (campylobacter, shigella, salmonella).
76
What is "sausage finger" and with what arthropathy is it associated?
Swelling of the DIP joints of hands associated with psoriatic arthritis.
77
Name 3 subsets of arthropathy associated with HLA B-27
Ankylosing spondylitis; Psoriatic arthritis; Reactive arthritis (Reiter syndrome). These are referred to as seronegative arthropathies
78
What is "bamboo spine"?
Fusion of spine segments seen in ankylosing spondylitis.
79
Infectious arthritis in a sexually active young adult is associated with what bacteria?
N. gonorrheae
80
Describe the arthritis seen with Neisseria infection.
Unilateral, migratory, usually involving the knee.
81
What is deposited in the joints in gout?
Monosodium urate crystals (NOT uric acid!)
82
Does breakdown of purines or pyrimidines lead to gout?
Purines (AMP and GMP)
83
What are the two basic ways that hyperuricemia can occur?
Overproduction of uric acid (high protein diet, myeloproliferative disorder, Lesch-Nyhan) Failure to filter and excrete uric acid from the kidney (renal insufficiency, thiazide/loop diuretics, alcohol binge)
84
From what compound and with what enzyme does the body make uric acid?
Xanthine oxidase metabolizes xanthine (product of purine metabolism) into uric acid.
85
What enzyme is deficient in Lesch-Nyhan syndrome and what happens in the disease?
HGPRT deficiency. As a result, the body can't salvage hypoxanthine (from AMP) and guanine (from GMP). As a result, xanthine, and thus uric acid production is greatly increased. This results in gout, self-mutilation, and developmental delay.
86
What is podagra?
Painful arthritis of the MTP joint of the great toe seen in acute gout.
87
What causes the acute inflammatory reaction in acute gout?
Monosodium urate crystals activating neutrophils.
88
Give two dietary triggers for an acute gout attack.
Consumption of excess meat (more purines) Consumption of excess alcohol (alcohol competes with uric acid for excretion in the kidney)
89
What is the hallmark of chronic gout?
Formation of tophi - white, chalky deposits of monosodium urate crystals in soft tissue or joints.
90
What are tophi?
White chalky deposits of monosodium urate crystals in soft tissues or joints seen in chronic gout.
91
What will be seen under the microscope with examination of gout crystals?
Needle-shaped crystals with negative birefringence (when crystals lay flat, they are yellow) under polarized light.
92
Needle-shaped crystals with negative birefringence under polarized light.
Gout
93
What color are gout crystals under parallel light?
Yellow
94
What deposits in the joints in pseudogout?
Calcium pyrophosphate
95
What will be seen under the microscope with examination of pseudogout crystals?
Rhomboid shaped crystals with weak positive birefringence under polarized light
96
Rhomboid shaped crystals with weak positive birefringence under polarized light.
Pseudogout.
97
What color are pseudogout crystals under parallel light?
Blue
98
What causes hypercalcemia in sarcoidosis?
Increased 1 alpha hydroxylation of vitamin D in epithelioid macrophages.
99
What else do you need to look for in a patient presenting with dermatomyositis?
Underlying cancer (particularly stomach)
100
Describe the weakness seen in a patient with dermatomyositis/polymyositis.
Bilateral proximal weakness (can't climb stairs or comb hair)
101
What is a heliotrope rash and with what disease is it associated?
Purple rash on the eyelids and face seen in dermatomyositis. (Note: it may be described as a malar rash - don't jump on SLE!)
102
What are Gottron's papules?
Red papules on the elbows, knuckles, and knees seen in dermatomyositis.
103
Describe the skin findings in dermatomyositis.
Heliotrope rash (purple rash on face and eyelids) and Gottron's papules (red papules seen on fingers, elbows, knuckles).
104
What antibody is seen in dermatomyositis?
Anti-Jo-1 antibody
105
Anti-Jo-1 antibody
Dermatomyositis/polymyositis
106
What is inflamed in dermatomyositis?
Perimisium
107
What antibody is seen in polymyositis?
Anti-Jo-1 antibody
108
What is the treatment for dermatomyositis/polymyositis?
Steroids
109
How is polymyositis differentiated from dermatomyositis?
Polymyositis has the same muscle symptoms (proximal weakness), but it will not have a heliotrope rash or Gottron's papules.
110
Describe the skin findings in polymyositis.
No skin findings - only have skin findings in dermatomyositis.
111
What cells cause inflammation in dermatomyositis?
CD4
112
What cells cause inflammation in polymyositis?
CD8
113
What is inflamed in polymyositis?
Endomysium of muscle
114
What replaces muscle in DMD?
Adipose tissue (causes pseudohypertrophy of calves)
115
What is deleted in DMD?
Dystrophin
116
What is the largest gene in the genome and why does this matter clinically?
Dystrophin gene - its size predisposes it to mutations (DMD/Becker).
117
What is the function of dystrophin?
Anchors muscle cytoskeleton to ECM.
118
What antibody is seen in MG?
Autoantibody against the postsynaptic Ach receptor at the NMJ.
119
List some clinical features of myasthenia gravis.
Muscle weakness that worsens with use and improves with rest, ptosis, diplopia, THYMOMA.
120
Thymoma or thymic hyperplasia is associated with..
Myasthenia gravis
121
Surgically, what can be done to improve symptoms of a patient with myasthenia gravis?
Removal of the thymus (thymoma or thymic hyperplasia).
122
What antibodies are seen in Lambert-Eaton syndrome?
Antibody against presynaptic calcium channel, which prevents calcium influx and release of Ach.
123
Patient is diagnosed with Lambert-Eaton syndrome. What else should you look for?
Small cell lung cancer.
124
Describe the weakness seen with Lambert-Eaton syndrome.
Proximal muscle weakness that improves with use. Eyes are spared.
125
What is the most common benign soft tissue tumor in adults?
Lipoma
126
What is the most common malignant soft tissue tumor in adults?
Liposarcoma
127
What is the characteristic cell in liposarcoma?
Lipoblast
128
Cardiac rhabdomyoma is associated with what disorder?
Tuberous sclerosis
129
What is the most common malignant soft tissue tumor in children?
Rhabdomyosarcoma
130
Biopsy shows desmin positive cells. Diagnosis?
Rhabdomyosarcoma (rhabdomyoblasts are desmin positive).
131
What is sarcoma botryoides?
Rhabdomyosarcoma in the vaginal canal in young females.
132
What is the MOA of allopurinol?
Inhibits Xanthine oxidase
133
What is the MOA of febuxostat?
Inhibits xanthine oxidase
134
What is the MOA of probenicid?
Decreases reabsorption of uric acid in the PCT
135
What is the MOA of colchicine?
Inhibits microtubule polymerization through stabilization of tubulin, resulting in decreased chemotaxis and degranulation of neutrophils.
136
What two drugs can be used in an attack of acute gout?
Indomethacin (NSAID) or colchicine (inhibits microtubule polymerization. Used in those that NSAIDs aren't tolerated)
137
What is etanercept?
A fusion protein that acts as a receptor for TNF-alpha used in inflammatory conditions (decoy receptor).
138
What are adalimumab/infliximab?
Anti- TNF alpha monoclonal anibodies used in inflammatory conditions.
139
What 3 drugs are used in chronic gout?
Allopurinol/febuxostat (xanthine oxidase inhibitors) Probenecid (decreases reabsorption of uric acid in PCT)
140
What is polymyalgia rheumatica?
Pain and stiffness in shoulders/hips with fever/malaise/weight loss. Does not cause muscular weakness. Associated with giant cell arteritis.
141
MOA/Use/SFX of bisphosphonates
MOA: Bind hydroxyapatite in bone, inhibiting osteoclasts; Uses: Osteoporosis, hypercalcemia, Paget's disease of the bone; SFX: corrosive esophagitis, osteonecrosis of the jaw.
142
MOA of zileuton
Inhibits lipooxygenase and production of all leukotrienes
143
MOA of zafirleukast/monteleukast
Inhibit production of LTC4, LTD4 specifically (inhibit bronchoconstriction)
144
Name the layers of the epidermis from the surface to the base
Californians Like Girls in String Bikinis
Stratum Corneum, Lucidum, Granulosum, Spinosum and Bassalis
145
WHat is the stem cell site in the epidermis?
Stratum basalis
146
Describe a sebaceous gland
Holocine secretion of sebum. Associated with a hair follicle
147
Describe a eccrine gland
Secretes sweat. Found throughout the body
148
Describe a apocrine gland
Secretes milky viscous fluid. Found in the axillae, genitalia and areolae. Does not become functional until puberty. Malodorous due to bacterial action
149
What are zone occludens?
Tight junctions, prevents paracellular movement of solutes
| Composed of claudins and occludins
150
What are zona adherens?
Adherens junction - located below tight junctions, forms a "belt" connecting actin cytoskeletons of adjacent cells with cadherins
Note - loss of E-cadherin promotes metastasis
151
What are macula adherens?
Desmosomes - structural support via keratin interactions
152
What are the autoantibodies against in pemphigus vulgaris?
Desmosomes
153
What are gap junctions?
Channel proteins called connexons permit electrical and chemical communication between cells
154
What are hemidesmosomes?
Connects keratin in basal cells to underlying basement membrane
155
What are the autoantibodies against in Bullous pemphigoid?
Hemidesmosomes
156
What are integrins?
Membrane proteins that maintain integrity of the basement membrane by binding to laminin in the basement membrane
157
What is the triad in a knee injury?
ACL, MCL and meniscus (classically the medial but lateral is more common)
due to a lateral force applied to a planted leg
158
If a patient has an abnormal passive abduction of the lower limb - what is wrong?
MCL tear
159
What does a positive McMurray circumduction test mean?
Medial meniscus injury
160
What is the landmark for a pudendal nerve block?
Ischial spine
161
What is the landmark for the appendix?
2/3 of the way from the umbilicus to the ASIS
162
What are the 4 muscles of the rotator cuff AND what is their action?
Supraspinatus - abducts the arm initially before the deltoid
Infraspinatus - laterally rotates the arm
Teres minor - adducts and laterally rotates the arm
Subscapularis - medially (internally) rotates and adducts the arm
163
What is most commonly injured of the rotator cuff muscles?
Supraspinatus
164
which rotator cuff muscle is most commonly injured in a pitching injury?
Infraspinatus
165
What nerves innervate the rotator cuff muscles?
C5-C6
166
Where does the supraspinatus muscle insert?
Greater tubercle of the humerus
167
What is a Hawkin's kennedy test?
impingement test - forward flex the shoulder and elbow to 90 degrees while passively internally rotating the shoulder - pain is positive
Usually positive with a supraspinatus muscle injury
168
A patient has an anterior shoulder dislocation - what have they most likely injured?
Axillary nerve and posterior circumflex artery
169
Which two wrist bones articulate with the distal radius?
Scaphoid and lunate - articulate only with the distal radius so they transmit the force of a FOOSH
170
What is the most commonly fractured carpal bone?
Scaphoid - prone to avascular necrosis owing to retrograde blood supply
171
What can occur with dislocation of the lunate bone?
Carpal tunnel syndrome
172
What nerve can be compressed in the axilla with incorrect use of a crutch?
Radial nerve
173
What nerve is compressed by supracondylar fracture of the humerus?
Median nerve
174
What nerve is compressed in pronator teres syndrome?
Median nerve
175
What nerve is injured with a fracture of the medial epicondyle of the humerus?
Ulnar nerve
176
where in the wrist can the ulnar nerve be injured?
Guyon's canal
177
What nerve can be injured by a fracture of the hook of hamate?
Ulnar nerve
can also be lesioned by trauma to the heel of the hand
178
Which nerve can be inured by a midshaft fracture of the humerus?
Radial nerve - it runs through the spiral groove ere
179
Which nerve can be injured by subluxation of the radius?
The deep branch of the radial nerve can be stretched
180
What is a Holstein-Lewis fracture?
Distal spiral humeral shaft fracture = radial nerve injury
181
What nerve is injured with fracture to the surgical neck of the humerus?
Axillary nerve and posterior humeral artery
Axillary nerve can also be injured with dislocation of the humerus and with intramuscular injections
182
How many tendons run through the carpal tunnel?
9 tendons
183
A patient has carpal tunnel syndrome how would you treat them with OMM?
Stretch the flexor retinaculum
184
what is seen with injury to the upper trunk of the brachial plexus?
Erb's palsy
185
What is seen with injury to the lower trunk of the brachial plexus?
Klumpke's palsy
186
What is seen with injury to the posterior cord of the brachial plexus?
Wrist drop
187
What is seen with injury to the long thoracic nerve?
winged scapula
due to serratus anterior loss - used for abduction above horizontal position
If this nerve was injured in mastectomy you would see winged scapula + lymphedema
188
What is seen with injury to the Axillary nerve?
deltoid paralysis
189
What is seen with injury to the radial nerve?
Saturday night palsy = wrist drop
190
What is seen with injury to the msculocutaneous branch of the brachial plexus?
Difficulty flexing the elbow, variable sensory loss
191
What is seen with injury to the median nerve at the brachial plexus?
Decreased thumb function - pope's blessing
192
What is seen with injur of the ulnar nerve at the brachial plexus?
Intrinsic muscles of the hand, claw hand
193
If a patient has a clavicle fracture - what protects them from injuring the brachial plexus?
Subclavius muscle
194
what is the job of the muscle spindle?
monitors muscle length
195
What is the functional unit of the muscle?
Extrafusal muscle fibers
196
What regulates the length of the muscle?
Intrafusal muscle fibers communicating with the muscle spindle
197
What is the job of the Golgi tendon?
Monitor tension
provides inhibitory Ib afferent feedback
198
What is the job of the gamma loop?
Regulates sensitivity of the reflex arc
199
which ligament is torn most commonly in an inversion ankle sprain?
Lateral ligaments effected
| Always Torn First ligament = Anterior TaloFibular ligament
200
what are the three ligaments of the lateral ligaments?
Anterior talofibular ligament
Calcaneal fibular ligament
Posterior talofibular ligament
201
Where do the wrist extensors attach?
Lateral epicondyle
| tennis elbow
202
Where do the wrist flexors attach?
medial epicondyle
| golfers elbow
203
what is the sympathetic innervation to the lower extremities?
T10-L2
204
Describe concentric contractions
muscle contractions that result in the approximation of the muscles origin and insertion
example - biceps curl
The force generated by a muscle exceeds the force applied to it
205
Describe eccentric contractions
Lengthening of the muscle during contraction due to an external force
206
Describe isolytic contraction
Muscle contraction against resistance while forcing the muscle to lengthen
the operators force is greater than the patients force
207
Describe isometric contraction
Muscle contraction that results in the increased tension without an approximation of the origin and insertion
Operators force will = the patients force
Example would be pushing against a stationary object
208
Describe Isokinetic contraction
Force of contraction changes the speed of contraction remains constant. These are rare in the body
209
Describe supination of the foot?
Adduction, inversion, platarflexion
210
Describe pronation of the foot?
Abduction, eversion and dorsiflexion
211
Describe the findings in erb duchenne palsy
Limb hands by side due to paralysis of the abductors
Limb is medially rotated due to paralysis of the lateral rotators
Forearm is pronated due to loss of the biceps
212
What are the nerves injured in erb duchenne palsy?
Upper trunk - Suprascapular N, Musculocutaneous N. and Axillary nerve
213
What is injured in a klumpke's palsy?
Lower trunk of brachial plexus (C8-T1) also injured in thoracic outlet syndrome
214
What are the findings in a patient with Klumpke's palsy?
Atrophy of the thenar and hypothenar eminences
Atrophy of the interossous muscles
Sensory deficits on the medial side of the forearm and hand
Disappearance of the radial pulse upon moving the head toward the ipsilateral side
215
What is the innervation of the axillary nerve
C5,6
216
What is the innervation of the Radial nerve?
C5-T1
217
What is the innervation of the median nerve?
C5-T1
218
What is the innervation of the Ulnar nerve?
C8-T1
219
What is the innervation of the musculocutaneous nerve?
C5-C7
220
Which nerve pierces the coracobrachialis muscle and runs between the biceps and brachialis?
Musculocutaneous nerve
221
Which nerve is responsible for the flexors and pronating the wrist?
Median nerve
222
Which nerve is injured with a midshaft fracture of the humerus?
Radial nerve
223
Which artery does the axillary nerve run with?
Posterior circumflex artery
224
What muscles does the Axillary nerve innervate?
Deltoid and teres minor
225
Where is the sensory deficit with a axillary nerve injury?
over the deltoid (lateral shoulder)
226
What does the radial nerve innervate?
```
BEST extensors
Brachioradialis
Extensors of the wrist and fingers
Supinator
Triceps
```
227
Which nerve innervates the abductor pollicus longus muscle?
Radial nerve
abductor pollicis brevis is by the median nerve
228
What does the median nerve innervate?
Opposition of the thumb, lateral finger flexion and wrist flexion
so the wrist flexors, thenar muscles (opponens pollicis, abductor pollicis brevis and flexor pollicis brevis) and lumbricals 1 and 2
229
Which nerve is responsible for medial finger flexion and wrist flexion?
Ulnar nerve
230
What is the sign with an ulnar nerve lesion?
Radial deviation of the wrist upon wrist flexion
231
What can cause ulnar claw?
Can be caused by long standing injury to the ulnar nerve at the hook of the hamate (FOOSH)
Distal ulnar nerve lesion leads to loss of medial lumbrical function leaving to inability to extend the 4th and 5th digits (clawing) when trying to open the hand
232
What is the median claw?
You have loss of lateral lumbraical function. 2nd and 3rd digits are clawed upon attempted finger extension
233
What is popes blessing?
Proximal median nerve lesion causes loss of lateral finger flexion and thumb opposition. When asked to make a fist, the 2nd and 3rd digits remain extended and thumb remains unopposed which looks like the hand of benediction
234
What does the median nerve innervate?
LOAF
| lumbricals 1 +2, opponens pollicis, abductor pollicis brevis and flexor pollicis brevis
235
What is the function of the dorsal interosseous muscles?
Abduct the fingers (DAB - dorsals ABduct)
236
What is the function of the palmar interosseous muscles?
Adduct the fingers (PAD - Palmar ADduct)
237
WHat is the function of the lumbricals?
Flex at the MCP joint and extend at the PIP and DIP joints
238
What can injure the obturator nerve? What is the result?
Anterior hip dislocation
Loss of thigh adduction and sensory loss on the medial thigh
239
What is the nerve levels of the Obturator nerve?
L2-4
240
What is the nerve levels of the femoral nerve?
L2-4
241
What is the nerve levels of the common peroneal nerve?
L4-S2
242
What is the nerve levesl of the Tibial nerve?
L4-S3
243
What is the nerve levels of the superior gluteal nerve?
L4-S1
244
What is the nerve levels of the inferior gluteal nerve?
L5-S2
245
How can you injure the femoral nerve? What are the effects?
Pelvic fracture
| Loss of thigh flexion and leg extension and loss of anterior thigh and medial leg sensory
246
How can you injure the common peroneal nerve? What is the motor and sensory loss?
Injured by trauma or compression of the lateral aspect of the leg or a fibular neck fracture
The patient will have loss of foot eversion and dorsiflexion resulting in loss of toe extension, foot drop, foot slap, and STEPPAGE GAIT (swing out gait)
They will have sensory loss of the anterolateral leg and dorsal aspect of the foot
The Peroneal nerve Everts and Dorsiflexes - if injured the foot is dropPED
247
How can you injure the Tibial nerve and what are the effects?
Knee trauma
results in loss of foot inversion and plantarflexion, toe flexion
loss of sensory on the sole of the foot
The Tibial nerve Inverts and Plantarflexes - if injured can't step on TIPtoes
248
How can you injure the superior gluteal nerve and what is the effect?
Posterior hip dislocation or polio.
Loss of thigh abduction (positive trendelenburg sign - CL hip drops when standing on leg ipsilateral to site of lesion)
249
How can you injure the inferior gluteal nerve and what is the effect?
Posterior hip dislocation
Can't jump, climb stairs or rise from a seated position. Can't push inferiorly (downward)
250
What are the levels of the sciatic nerve?
L4-S3 - runs down the posterior thigh and splits into the common peroneal and tibial nerves
251
How is the posterior cruciate ligament commonly injured?
Hyperflexion injury
Hyperextension injury causes an ACL tear
252
When the quads tighten - what happens in a posterior cruciate ligament tear?
The tibia translates anteriorly
| The quads insert on the tibia
253
What is the Q angle?
Angle between the femur axis and tibia axis - is normally 10-12 degrees
A Q angle > 20: genu valgus (knock knee) can occur due to weak vastus medialis muscles
A Q angle <10: genu carum
254
What are the angles of inclination?
Angles between the shaft of the fermur and femoral neck
normal is 120-135
>135: coxa valgus
<120: coxa varum
255
What muscles make up the hamstrings?
Semitendinosus, semimembranosus, biceps femoris
256
What is the sural nerve?
Sensory only to the posterior lateral leg and lateral side of foot
257
how do you test the IT band?
Ober's test
258
What happens to membrane excitability if you decreased extracellular calcium?
Increased membrane excitability
259
What in the muscle fiber shortens with contraction?
H band and I band
260
what drug blocks the ryanodine receptor?
Dantrolene
ryanodine receptor is located on the sarcoplasmic reticulum
261
What remains a constant length with contraction of a muscle fiber?
A band remainds constant length
262
Describe Type 1 muscle fibers
Slow twitch - red fibers, resulting from increased mitochondria and myoglobin concentration (increased oxidative phosphorylation) leading to sustained contraction
examples -calf muscles or abdominal muscles
263
Describe Type 2 muscle fibers
Fast twitch muscles - white fibers resulting from decreased mitochondria and myoglobin concentration (increased anaerobic glycolysis) - weight training results in hypertrophy of fast-twitch muscle fibers
264
what happens when ATP binds the myosin head?
Causes released of myosin from the actin filament
this is why a lack of ATP results in rigor mortis
265
WHat bones participate in endochrondal ossification?
Bones of the axial and appendicular skeleton, and base of the skull
Cartilagenous model of bone is first made by chrondrocytes - osteoclasts and osteoblasts later replace with woven bone and then remodel to lamellar bone. In adults woven bone occurs after fractures and in Paget's disease
266
What is Membranous ossification?
Occurs in the bones of the calvarium and facial bones. Woven bone is formed directly without cartilage. Later remodeled to lamellar bone
267
What are osteoblasts?
Build bone by secreting collagen and catalyzing mineralization - osteoblasts get incorporated into the bone and become osteocytes
268
What are osteoclasts
Multinucleated cells that dissolve bone by secreting acid and collagenases - type of macrophage
269
What is the difference between high and low levels of PTH?
At low, intermittent levels, exerts anabolic effects (building bone) on osteoblasts and clasts
Chronic high levels (primary hyperparathyroidism) causes catabolic effects (osteitis fibrosa cystica)
270
What are the effects on bone by estrogen?
estrogen inhibits apoptosis in bone-forming osteoblasts and induces apoptosis in bone resorbing osteoclasts. Under estrogen deficiency - excess remodeling cycles and bone resorption leads to osteoporosis
271
what is responsible for linear growth?
Epiphyseal cartilage - growth plate
| linear growth stops when the epiphysis fuses with the metaphysis (plates close)
272
What is the effect of sex steroids on linear growth?
sex steroids initially increased linear growth but they also encourage closure of the epiphyseal growth plates
273
failure of longitudinal bone growth (endochrondral ossification) but normal membranous ossification
Achondroplasia - most common cause of dwarfism
failed endochrondral ossification = short limbs
normal membranous ossification = normal (large) head compared to limbs
274
What is the defect in Achondroplasia?
Constitutive activation of fibroblast growth factor receptor (FGFR3) actually inhibits chondrocyte proliferation (you don't get the laying down of the cartilage frame)
due to advanced paternal age and also is autosomal dominant inheritance
275
Describe osteoporosis
Trabecular (spongy) bone loses mass and interconnections despite normal bone mineralization and lab values
can lead to acute vertebral crush fractures - acute back pain loss of height and kyphosis
276
Describe Type 1 osteoporosis?
Postmenopausal - increased bone resportion due to decreased estrogen levels
examples - femoral neck fracture, distal radius fracture (colles' fracture)
277
Describe Type 2 osteoporosis?
Senile osteoporosis - affects men and women over the age of 70
278
Describe Osteopetrosis
Failure of normal bone resportion due to defective osteoclasts leading to thickened dense bones that are prone to fracture.
The bone fills the marrow space leading to pancytopenia and extramedullary hematopoiesis
279
What is the mutation in Osteopetrosis?
Impaired osteoclasts
Commonly due to carbonic anhydrase II mutation leading to impaired ability of osteoclasts to generate an acidic environment for resorbing bone
bone marrow transplant would be potentially curative
280
Describe osteomalacia and rickets
Vitamin D deficiency
Osteomalacia is seen in adults and rickets in kids
due to defective mineralization/calcification of osteoid leading to soft bones that bow out
281
what is hyperactive in osteomalacia and rickets?
osteoblast - you have increased alkaline phosphatase (since osteoblast require alkaline environment to work)
282
What is Paget's disease of bone (Osteitis deformans)?
Common, localized disorder of bone remodeling caused by increase in both osteoblastic and osteoclastic activity
283
What is the pattern seen in Paget's disease (Osteitis deformans)?
Mosaic ("woven" bone pattern - long bone chalk-stick fractures.
284
What are possible risks seen in Paget's disease (Osteitis deformans)?
High cardiac output heart failure - due to increased blood flow from increased arteriovenous shunts
also increased risk of osteogenic sarcoma
285
How can phenytoin lead to deficiencies in Vitamin D?
Phenytoin induces P450 system which metabolizes Vitamin D
286
A patient with both lytic and sclerotic areas of bone
Paget's disease of bone (Osteitis deformans)
287
What are the lab findings in a patient with Osteoporosis?
all NORMAL! just a decreased in bone mass due to decreased osteoblast activity
288
What are the lab findings in a patient with Osteopetrosis?
Decreased serum calcium and increased ALP - has thickened denes bone due to decreased osteoclast activity
289
What are the lab findings in a patient with Osteomalacia/Rickets?
Decreased serum calcium and phosphate and increased ALP and PTH
patient will have soft bones due to defective mineralization
290
What are the lab findings in a patient with Osteitis fibrosa cystica?
Increased serum calcium, ALP and PTH and decreased phosphate
The patient will have brown tumors of hyperparathyroidism (due to XS osteoclast activity)
291
What are the lab findings in a patient with Paget's disease of the bone?
Increased ALP is possible
| due to abnormal bone architecture
292
Name the Bone tumor: Occurs in 20-40 yo at the epiphyseal end of long bones
Giant cell tumor (Osteoclastoma)
293
Name the Bone tumor: Double bubble or soap bubble appearance on X ray
Giant cell tumor - AKA osteoCLastoma
CL - clean = soap
294
Name the Bone tumor: Locally aggressive benign tumor often around the distal femur, proximal tibial region
Giant cell tumor - AKA osteoclastoma
295
Name the Bone tumor: Most common benign tumor and occurs in males less than 25 years old
Osteochondroma
malignant transformation to chondrosarcoma is rare
296
Name the Bone tumor: Mature bone with cartilaginous cap that commonly originates from long metaphysis.
Osteochondroma
osteoCHondroma = CHunk of bone
297
Name the Bone tumor: due to a defective Rb suppressor gene
Osteosarcoma
298
Name the Bone tumor: Second most common primary malignant bone tumor (after multiple myeloma)
Osteosarcoma
299
Name the Bone tumor: 10-20 yo more common in males than females - occurs in the metaphysis of long bones, often around the distal femur or proximal tibia. This is a malignant bone tumor
Osteosarcoma
300
Name the Bone tumor: Has Codman's triangle due to elevation of periosteum or sunburst pattern on Xray. It's aggressive and treated with surgical en bloc resection (with limb salvage) and chemotherapy
OsteoSarComa
S- sunburst
C - codmans triangle
301
Name the Bone tumor: Occurs in boys less than 15 yo, commonly appears in the diaphysis of long bones, pelvis, scapula and ribs
Ewing's sarcoma
302
Name the Bone tumor: Contains anaplastic small blue cell malignat tumor, extremely aggressive with early mets but it's responsive to chemo
Ewing's sarcoma
303
Name the Bone tumor: Onion skin appearance in bone and associated with t(11;22) translocation
Ewing's sarcoma
onion rings and wings
onion skin appearance = concentric formation of new bone layers
304
Name the Bone tumor: Occurs in men 30-60 years old and is usually located in the pelvis, spine, scapula, humerus, tibia or femur
Chrondrosarcoma
305
Name the Bone tumor: Malignant cartilaginous tumor that may occur from primary origin or from an osteochondroma.
Chondrosarcoma
306
Name the Bone tumor: Expansile glistening mass within the medullary cavity of diaphysis
Chrondrosarcoma
307
What part of the bone does osteomyelitis most commonly occur?
Metaphysis of long bones
308
What is the cause of osteoarthritis?
Mechanical cause - joint wear and tear that destroys the articular cartilage
309
What is the cause of rheumatoid arthritis?
Autoimmune cause - inflammatory destruction of the synovial joints - type 3 HS
310
Which disease has no DIP involvement?
Rheumatoid arthritis
| usually involves just the MCP and PIP joints
311
What is rheumatoid factor?
IgM antibody against the Fc portion of IgG
312
What HLA is associated with rheumatoid arthritis?
HLA-DR4
313
Compare the treatment of osteoarthritis with RA?
Osteoarthritis - NSAIDs, intra-articular glucocoritcoids
RA - NSAIDs, glucocorticoids, disease-modifying agents (methotrexate, sulfasalazine, TNF-alpha inhibitors)
314
describe a swan neck deformity
Extended PIP and flexed DIP
315
describe a boutonniere deformity
Flexed PIP and extended DIP - the extensor tendon on the back of the finger splits do that the PIP sticks out
316
What is the syndrome that has lymphocytic infiltration of exocrine glands especially the lacrimal and salivary glands?
Sjogren's syndrome
317
What are the increased risks in Sjogren's syndrome?
dental caries, increased risk of B cell lymphoma
Sjogren's can also be associated with rheumatoid arthritis
(Can't see (dry eyes), can't spit (dry mouth), can't climb up a ship)
318
What are the autoantibodies seen in Sjogren's syndrome?
Autoantibodies to ribonucleoprotein antigens: anti-Ro and anti-La
319
Why can alcohol precipitate a gout attack?
Alcohol metabolites compete for the same excretion sites as uric acid in the kidney
320
which diuretics can exacerbate gout by decreased uric acid excretion?
Loop diuretics and Thiazide diuretics
321
where are common locations to get tophus formation with gout?
external ear, olecranon bursa or Achilles tendon
note tat tophi are uric acid deposits - they are NOT inflamed
322
List the treatments for acute gout
NSAIDs (indomethacin), glucocorticoids and colchicine
323
List the treatments for chronic gout
Xanthine oxidase inhibitors like allopurinol or febuxostat
324
can you use aspirin in a gout patient?
NO it's contraindicated - both uric acid and aspirin compete at renal transporters resulting in higher serum levels of uric acid
Sulfonamides, penicillin and thiazide diuretics compete at this same spot
325
What is seen in joint aspiration for a patent with gout vs a patient with pseudogout?
Gout - negative birefringence
| pseudogout - positive birefringence
326
List four causes of osteonecrosis?
This is infarction of the bone and marrow.
Caused by trauma, high dose corticosteroids, alcoholism and sickle cell
most common site is the femoral head
327
What is seronegative spondyloarthropathies?
Arthritis without rheumatoid factor
associated with HLA-B27
328
When do you see pencil-in-cup deformities on xray?
Psoriatic arthritis
| along with sausage fingers
329
What are syndesmophytes?
Like osteophytes but they are seen in ankylosing spondylitis
330
What is the classic triad seen in Reiter's syndrome?
Conjunctivities with anterior uveitis, urethritis, arthritis - can't see, can't pee can't climb a tree
331
What can cause reactive arthritis?
Post-GI (shigella, salmonella, Yersinia, campylobacter, clostridium) or with chlamydial infections
332
How do you treat ankylosing spondylitis?
Indomethacin primary
secondary is sulfasalazine, or anti-TNF alpha agents
333
Nephritis is the most common cause of death in SLE patients - what are the problems with the kidneys?
Nephrotic - membranous glomerulonephritis
| Nephritic - Diffuse proliferative glomerulonephritis
334
What are the autoantibodies seen in SLE?
- ANA - screening but not specific
- anti-DS DNA - specific poor prognosis
anti-smith antibodies very specific but not prognostic
anti-histone antibodies - drug induced lupus
335
Why do SLE patients test false positive on syphilis tests?
due to antiphospholipid antibodies which cross react with cardiolipin used in the tests
336
What are the presentations in SLE?
fever, fatigue, weight loss, libman sacs endocarditis, hilar adenopathy, Raynaud's phenomenon
337
What is the cause of an SLE patient developing autoimmune hemolytic anemia?
Warm IgG antibodies - binds to surface of RBCs
| patients will have a positive direct Coombs test
338
Describe Sarcoidosis
"A GRUELING DISEASE"
- ACE increased
- Granulomas (non caseating)
- Rheumatoid arthritis
- Uveitis
- Erythema nodosum (tibial)
- Lymphadenopathy (bilateral, HILAR)
- Idiopathic
- Noncaseating granulomas
- Gamma globulinemia
- Vitamin D increased - causing hypercalcemia
339
A patient presents with bilateral hilar adenopathy and reticular opacities - what should you think?
Sarcoidosis
340
Why do patients with sarcoidosis have hypercalcemia?
They have increased vitamin D due to elevated 1 alpha hydroxylase mediated vitamin D activation in epithelioid macrophages
341
What is the treatment for a patient with sarcoidosis?
steroids
342
What is polymyalgia rheumatica?
Pain and stiffness in shoulder and hip joints often with fever, malaise and weight loss. does not cause muscular weakness.
More common in women >50yo associated with temporal giant cell arteritis
patients will have increased ESR but normal CK
343
How do you treat a patient with polymyalgia rheumatica?
low dose corticosteroids
344
Describe Polymyositis
Progressiev symmetric proximal muscle weakness, characterized by endomysial inflammation with CD8+ T cells - most often involves the shoulders and pelvic girdle
345
Describe dermatomyositis
Similar to polymyositis but also involves a malar rash. Gottrons papules (red scaly papules on knuckles or knees/elbows), heliotrope rash, shawl and face rash, mechanic's hands.
Increased risk of occul malignancy. Perimysial inflammation and atrophy with CD4+ T cells
346
what are some findings in patients with Polymyositis or Dermatomyositis?
Increased CK, positive ANA, positive anti-Jo-1 antibodies, increased aldolase
347
What is Myasthenia gravis associated with?
Thymoma or thymic hyperplasia
348
how do you diagnose myasthenia gravis?
Tensilon test - edrophonium (fast acting)
349
How do you treat myasthenia gravis?
Pyridostigmine - anticholinesterase
350
Describe 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
351
What is scleroderma?
Systemic sclerosis - excessive fibrosis and collagen deposition throughout the body
352
Describe diffuse scleroderma
Widespread skin involvement, rapid progression, early visceral involvement
associated with anti-DNA topoisomerase I antibody
353
Describe CREST scleroderma
CREST
Calcinosis, Raynaud phenomenon, Esophgeal dysmotlity, Sclerodactyly, Telangiectasia
Limited skin involvement, often confined to fingers and face
More benign than diffuse scleroderma. associated with anti-Centromere antibody
354
Describe a macule
flat lesion with well circumscribed change in skin color <5mm
examples: freckles, labial macule
355
Describe a patch
Macule >5mm
| examples: large birthmark (congenital nevus)
356
Describe a papule
elevated solid skin lesion <5mm
examples: mole (nevus), acne
357
Describe a plaque
Papule >5mm
| ex: psoriasis
358
Describe a vesicle
Small fluid containing blister <5mm
| examples: chicken pox or shingles
359
Describe a bulla
Large fluid containing blister >5mm
| Examples: bullous pemphigoid
360
Describe a pustule
Vesicle containing pus
| ex: pustular psoriasis
361
Describe a wheal
Transient smooth papule or plaque
like a hive or urticaria
362
Describe a scale
Flaking off of stratum corneum
Ex: eczema, psoriasis, SCC
363
Describe a crust?
Dry exudate
example: impetigo
364
What is hyperkeratosis?
increased thickness of the stratum corneum
365
What is Parakeratosis?
hjyperkeratosis with retention of nuclei in stratum corneum
366
What is acantholysis?
Separation of epidermal cells
367
What is acanthosis?
Epidermal hyperplasia with increased spinosum
368
What is dermatitis
Inflammation of the skin
369
Describe albinism
Normal melanocyte number with decreased melanin production due to decreased tyrosinase activity - can also be casued by fairle of neural crest cell migration
370
Describe Melasma
AKA chloasma
| Hyperpigmentation associated with pregnancy ("mask of pregnancy") or OCP use
371
Describe Vitiligo
Irregular areas of complete depigmentation caused by a decreased in melanocytes
372
Describe Verrucae
Warts caused by HPV.
they are soft, tan-colored, cauliflower like papules. Epidermal hyperplasia, hyperkeratosis, KOILOCYTOSIS
Called condyloma accuminatum on the genitals
373
What is melanocytic nevus?
common mole. Benign, but melanoma can arise in congenital or atypical moles. Intradermal nevi are popular
junctional nevi are flat macules
374
What is an ephelis?
Freckle - normal number of melanocytes but increased melanin pigment
375
What is atopic dermatitis?
Eczema
Pruritic eruption commonly on skin FLEXURES
often associated with other atopic diseases
usually starts ont he face in infancy and often appears in the antecubital fossa thereafter
376
How can you treat atopic dermatitis?
Calcineurin inhibitors (tacrolimus), steroids, antihistamine
377
What is allergic contact dermatitis?
Type IV hypesensitivity reaction that follows exposure to allergen
378
Describe Psoriasis
Papules and plaques with silver scaling especially on knees and elbos (extensor surfaces)
Acanthosis with parakeratotic scaling (nuclei still in stratum corneum) you have increased stratum spinosum and decreased stratum granulosum
379
What do you see Auspitz sign with?
Psoriasis
380
Describe Seborrheic Keratosis
Flat, greasy pigmented squamous epithelial proliferation with keratin filled cysts that looks stuck on
benign
381
What is lesser-Trelat sign?
Sudden appearance of multiple seborrheic keratosis, indicating an underlying malignancy - commonly GI or lymphoid (gastric cancer)
382
Describe Pemphigus Vulgaris?
"DAMN is a VULGAR word"
Desmosomes - IgG antibodies against desmoglein 3
Acantholysis - loss of intracellular connections - thin intraepidermal ullae causing flaccid blisters
Mouth - involves ORAL mucosa and skin
Nikolsky's sign - separation of epidermis upon manual stroking of skin
383
Describe Bullous pemphigoid?
IgG antibody against hemidesmosomes - epidermal basement membrane so you have linear immunofluorescence
Eosinophils with tense blisters (negative Nikolski's sign
does not involve oral mucosa
384
Describe dermatitis herpetiformis?
Deposits of IgA at the tips of dermal papillae
associated with celiac disease
intensely itchy
385
What is associated with erythema multiforme?
Infections - HSV, mycoplasma pneumonia
Drugs - sulfa drugs, beta lactams, phenytoin
cancers
autoimmune disease
386
What is toxic epidermal necrolysis?
A more severe form of stevens-johnson syndrome with >30% of the body surface area involved
387
What is stevens-johnson syndrome?
Characterized by fever, bulla formation and necrosis, sloughing of skin and a high mortality rate
388
What is acanthosis nigricans?
Epidermal hyperplasia (of stratum spinosum) causing symmetrical hyperpigmented velvety thickening of the skin especially on the neck or axilla
389
What can cause acanthosis nigricans?
Hyperinsulinemia (diabetes, obesity, Cuhsing's syndrome)
| and visceral malignancy
390
What is Actinic keratosis?
Results from proliferation of atypical epidermal keratinocytes
premalignant lesions caused by sun exposure - small rough erythematous or brownish papules or plaques.
391
What is the risk of Actinic keratosis?
May develop into squamous cell carcinoma - proportional to the degree of epithelial dysplasia
treat with 5-FU or cryoablation
392
What is erythema nodosum?
Inflammatory lesions of subcutaneous fat
| usually on the anterior shins
393
What is erythema nodosum associated with?
Sarcoidosis, coccidioidomycosis, histoplasmosis, TB ,strep infections, leprosy, and crohn's disease
394
What are the findings in a patient with Lichen planus?
```
6 Ps
Pruritic
Purple
Polygonal Planar Papules and Plaques
Sawtooth infiltrate of lymphocytes at the dermal-epidermal junction
```
395
What is lichen planus associated with?
Hepatitis C
396
What is pityriasis rosea?
"herald patch" followed days later by "Christmas tree" distribution
Multiple plaques with collarette scale
Self resolving in 6- 8 weeks
397
What is pityriasis rosea due to?
Reactivation of HHV-7 or HHV-6
398
What is a sunburn?
UV irradiation causes DNA mutations, inducing apoptosis of keratinocytes
UVA is dominant in tanning and photoaging
UVB is dominant in sunburn
399
What can sunburn lead to?
Impetigo, and skin cancers
400
What is cellulitis?
Acute painful spreading infection of the dermis and subcutaneous tissues - usually from S pyogenes or S aureus
Often starts with a break in the skin from trauma or another infection
401
Describe staphylococcal scalded skin syndrome?
Exotoxin destroys keratinocyte attachments in the stratum granulosum only (vs toxic epidermal necrolysis which destroys the epidermal dermal junction)
The sloughing of SSSS will heal completely
402
Are there bacteria in the blisters of a kin with staphylococcal scalded skin syndrome?
No
403
What is hairy leukoplakia?
White, painless plaques on the tongue that cannot be scraped off - EBV mediated - occurs in HIV positive patients
404
Name the skin cancer: Most common skin cancer
Basal cell carcinoma
405
Name the skin cancer: Pink, pearly nodules with telangiectasias and rolled borders and central crusting or ulceration
Basal cell carcinoma
406
Name the skin cancer: Palisading nuclear arrangements at the periphery of tumor cell clusters
Basal cell carcinoma
surgical resection is generally curative
407
Name the skin cancer: Second most common skin cancer
Squamous cell carcinoma
408
Name the skin cancer: associated with arsenic exposure commonly occurs on the face or lower lip, ears, hands
Squamous cell carcinoma
409
Name the skin cancer: Locally invasive but may spread to lymph nodes and will rarely metastasize
Squamous cell carcinoma
410
Name the skin cancer: Ulcerative red lesions with frequent scale. associated with chronic draining sinuses
Squamous cell carcinoma
411
Name the skin cancer: Keratin pearls
Squamous cell carcinoma
412
Name the skin cancer: A variant of squamous cell carcinoma that grows rapidly and may regress spontaneously
Keratoacanthoma
413
Name the skin cancer: Common tumor with significant risk of metastasis
Melanoma
414
Name the skin cancer: S-100 positieve
Melanoma
415
Name the skin cancer: Often drive by activating mutation in BRAF kinase.
Melanoma
416
Metastatic or unresectable melanoma in patients with BRAF V600E mutation may benefit from what?
Vemurafenib - a BRAF kinase inhibitor
417
What is the function of LTB4?
Neutrophil chemotaxis
418
What is the function of LTC4 and LTD4 and E4?
Bronchoconstriction, vasoconstriction, contraction of smooth muscle and increased vascular permeability
419
What is the function of PGI2 (Prostacyclin)?
Decreases platelet aggregation, decreases vascular tone, decreases bronchial tone, decreases uterine tone
420
What is the function of Prostaglandins PGE2 and PGF2alpha?
Increases uterine tone
decrease vascular tone
decreases bronchial tone
421
What is the function of TXA2?
Increases platelet aggregation
increases vascular tone
increases bronchial tone
422
How is aspirin different from acetaminophen?
Aspirin inhibits thromboxane production while acetaminophen does not
acetaminophen has NO anti-inflammatory or anti-platelet effects unlike aspirin which does
423
What is the MOA of acetaminophen?
Reversibly inhibits cyclooxygenase mostly in the CNS - it's inactivated peripherally
It decreases fever by reducing prostaglandin levels
424
What is the clinical use of acetaminophen?
Antipyretic, analgesic but not anti-inflammatory
| used instead of aspirin to avoid Reye's syndrome in children with a viral infection
425
What is the toxicity associated with acetaminophen overdose?
Hepatic necrosis - acetaminophen metabolite (NAPQI) depletes glutathione and forms toxic tissue adducts in the liver
N-acetylcysteine is the antidote which regenerates glutathione
426
What is the MOA of aspirin?
Irreversible inhibits cyclooxygenase (COX 1 and 2) by acetylation which decreases synthesis of both TXA2 and prostaglandins
increase bleeding time but no effect on PT or PTT
It's a type of NSAID
427
What is the clinical use of aspirin?
```
Low dose (<300 mg/day) causes decreased platelet aggregation
Intermediate dose - causes antipyretic and analgesic
high dose is anti-inflammatory
```
428
What is the toxicity of aspirin?
Gastric ulcers, tinnitus
Chronic use can lead to acute renal failure, interstitial nephritis and upper GI bleeding
Risk of Reyes syndrome in children treated with aspirin for viral infection
also stimulates respiratory centers causing hyperventilation and respiratory alkalosis
429
List some NSAIDs
Ibuprofen, naproxen, indomethacin, ketorolac, diclofenac
430
what is the MOA of NSAIDs?
reversibly inhibits cyclooxygenase 1 and 2 - blocks prostaglandin synthesis
431
What is the clinical use for NSAIDs?
Antipyretic analgesic and anti-inflammatory
| indomethacin can be used to close PDA
432
What is the toxicity of NSAIDs?
Interstitial nephritis, gastric ulcer (prostaglandins protect gastric mucosa), renal ischemia (PGs vasodilate afferent arteriole)
433
What is celecoxib?
COX2 inhibitor
spares COX-1 so you shouldn't see corrosive effects on GI lining and you also spare the platelet function since TXA2 is dependent on COX1
434
What is Alendronate?
Bisphosphonates
435
What is the MOA of bisphosphonates?
Pyrophosphate analog that binds hydroxyapatite in bone inhibiting osteoclast activity
436
What is the clinical use of bisphosphonates?
osteoporosis, hypercalcemia, paget's disease of the bone
437
What is the toxicity seen in Bisphosphonates?
Corrosive esophagitis, osteonecrosis of the jaw
438
What is one problem associated with using Allopurinol?
increases concentrations of azathioprine and 6-MP which are both normally metabolized by xanthine oxidase
439
How does probenecid work?
Inhibits reabsorption of uric acid in the proximal convoluted tubule
440
How does Colchicine work?
Binds and stabilizes tubulin to inhibit polymerization, impairing leukocyte chemotaxis and degranulation
441
What is the problem with TNF-alpha inhibitors?
All TNF-alpha inhibitors predispose to infection including reactivation of latent TB since TNF blockage prevents activation of macrophages and destruction of phagocytosed microbes
ALWAYS CHEK A PPD BEFORE STARTING A TNFalpha INHIBITOR!
442
What is the MOA of etanercept?
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Fusion protein (receptor for TNFalpha and IgG1 Fc) produced by recombinant DNA
EtancerCEPT is a TNF decoy reCEPTor
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443
What is the clinical use for etanercept?
Rheumatoid arthritis, psoriasis, ankylosing spondylitis
444
What is the MOA of infliximab and adalimumab?
Anti-TNF alpha monoclonal antibody
445
What is the clinical use of infliximab and adalimumab?
Crohn's disease, rheumatoid arthritis, ankylosing spondylitis, psoriasis
446
Describe the Thompson test
Squeeze the calf of the suspected injured leg while the patient lies prone
Test is positive if the foot doesn't plantarflex in response
A popping sound is more typical for Achilles tendon rupture than an ankle problem
