Rheumatology and Dermatology Flashcards
1
Q
What are some possible modes of treatment for atopic dermatitis (eczema)?
A
- Calcineurin inhibitors: tacrolismus, pimecrolismus
- Topical steroids
- Antibiotics for open lesions
- Antihistamines
- Leukotriene inhibitors: montelukast
- UV light therapy
- Systemic steroids
- Immunosuppressive drugs: methotrexate, cyclosporin, azathioprine
2
Q
How does one diagnose osteoporosis?
A
Bone mineral density test (DEXA: dual energy X-ray absorptiometry): T-score <= 2.5
3
Q
What are the possible complications of osteoporosis?
A
- Vertebral crush fractures
>> Acute back pain
>> Loss of height
>> Kyphosis - Pathological fractures
>> Femoral neck fracture
>> Distal radius (Colles) fracture
4
Q
What are the possible treatments for osteoporosis?
A
>> GO-TO regimen: bisphosphonate +/- SERM
- Bisphosphonates (e.g. risendronate, etidronate, alendronate etc.)
- PTH (e.g. teriparatide) - not to exceed 2 years, and must take bisphosphonate after stopping PTH to maintain BMD
- SERM (e.g. raloxifene)
- Testosterone/conjugated estrogen replacement
- Calcitonin spray - Denosumab
5
Q
What are the side effects of bisphosphonates?
A
- Errosive esophagitis: needs to remain upright 30 minutes after drug intake
- Osteonecrosis of the jaw
6
Q
What are the indications for bisphosphonates?
A
- Osteoporosis
- Paget’s disease of the bone
- Humoral hypercalcemia of malignancy
7
Q
What are the possible complications of osteopetrosis?
A
- Pathological fractures
- Narrowed foramina
>> Cranial nerve impingement
>> Cranial nerve palsies - Marrow infiltration
>> Pancytopenia
>> Extramedullary hematopoiesis
8
Q
What are some presenting features of Paget disease of bone?
A
- Increasing HAT SIZE – hats getting too tight
- Narrowing of the auditory foramen: hearing loss
- Bone pain and deformities
- Long bone chalk-stick fractures >> Increased risk for osteosarcoma
9
Q
What are the stages of Paget disease of bone?
A
- Lytic: increased osteoclastic activity
- Mixed: increased both osteoclastic/osteoblastic activity
- Sclerotic: increased osteoblastic activity
- Quiescent: minimal osteoclastic/osteoblastic activity
10
Q
What is the treatment for Paget disease of bone?
A
Bisphosphonates: alendronate, risendronate etc.
11
Q
What are the underlying etiologies of osteitis fibrosa cystica?
A
- Hyperparathyroidism
- Primary pseudohypoparathyroidism (Albright hereditary osteodystrophy)
>> PTH increased >> increased bone turnover with increased osteoclastic activity
12
Q
What is the defining histological feature of osteitis fibrosa cystica?
A
“Brown tumours” in bone: cystic spaces lined by osteoclasts filled with fibrous stroma and blood
13
Q
What are the features of McCune-Albright Syndrome?
A
- Cafe au lait spots
- Early/Precocious Puberty
- Abnormal Bone: polyostotic fibrous dysplasia (bone is replaced by collagen and fibroblasts with irregular bony trabeculae)
14
Q
What is the most common type of hip dislocation? What is the most common cause of the above type?
A
Posterior dislocation of the hip
- Motor vehicle accident: when the knee is flexed and hips slightly abducted –> knee hits the dashboard
15
Q
What structures can be damaged in a posterior dislocation of the hip?
A
- Medial circumflex femoral artery
- Lateral circumflex femoral artery
- Femoral vein
- Femoral nerve
- Head of femur
16
Q
What is the most common cause of the unhappy triad?
A
Common contact sports injury
- Lateral force applied to a planted leg
17
Q
What is the unhappy triad?
A
- MCL
- ACL
- Medial or lateral lemniscus
>> Lateral lemniscus in 56%
>> Medial lemniscus in 44%
18
Q
Which cell type do chondrocytes originate from? Which cells do they share this origin?
A
Mesenchymal stem cells
- Osteoblasts
- Adipocytes
19
Q
What is the leading cause of knee pain in patients under age 45?
A
Patellofemoral syndrome
20
Q
What is the treatment for patellofemoral syndrome?
A
- Strengthening the quadriceps
- Stretching exercises
>> Hamstrings
>> Calves
>> Hip
>> Iliotibial band - Minimize activities that put excessive stress on the knee: squatting, kneeling, jogging, stop and go sports
- Maximize walking and other low-impact exercise
21
Q
What are the two types of bursitis that can occur at the knee?
A
- Prepatellar bursitis: housemaid’s knee
- Infrapatellar bursitis: clergyman’s knee
22
Q
What are the ligaments most commonly affected in an ankle sprain?
A
- Anterior talofibular ligament
- Calcaneofibular ligament
- Posterior talofibular ligament
23
Q
What is the management for ankle sprain?
A
RICE
- Rest
- Ice: 20 minutes every 2 hours for the first 48 hours
- Compression
- Elevation
24
Q
How does plantar fasciitis present?
A
- Pain beneath calcaneus: “Heel pain”
- Pain in the medial arch
- Pain worse with first steps in the morning and after weight-bearing
- Local point tenderness at the medial tubercle of the calcaneus
25
What is the treatment for plantar fasciitis?
Medications
- NSAIDs
- Local steroid injection
Physiotherapy
- Dorsiflexion with night splints
- Stretching of the plantar fascia and Achilles tendon
- OTC heel inserts
Surgery
- Surgical release of the plantar fascia in severe cases
26
What are the muscles of the rotator cuff? How does one test their power?
SItS
- Supraspinatus
\>\> Initial 15 degree abduction of the arm
\>\> Test: empty beer can test
- Infraspinatus and teres minor
\>\> External rotation
\>\> Test: external rotation against resistance
- Subscapularis
\>\> Internal rotation
\>\> Test: lift-off test
27
How does one test for shoulder impingement syndrome?
- Jobe's test (Empty beer can test) -- right-most
- Hawkin's test -- middle
28
What is the difference between shoulder separation and shoulder dislocation?
Shoulder separation: separation of the clavicle from the acromion and the coracoid process
Shoulder dislocation: separation of the humeral head from the glenoid cavity
29
What structures can be damaged in an anterior shoulder dislocation? MUST KNOW!
- Axillary nerve: test by testing deltoid cutaneous senses
- Posterior circumflex humeral artery
- Supraspinatus tendon
- Bankart lesion \>\> Anterior glenohumeral ligament and glenoid labrum separation from the articular surface of the anterior glenoid neck
- Hill-Sachs lesion \>\> Posterolateral humeral head defect due to abrasion against the anterior rim of the glenoid
30
What are the two types of epicondylitis?
Lateral epicondylitis
- "Tennis elbow"
- Tears in wrist extensor tendons
Medial epicondylitis
- "Golfer's elbow"
- Tears in wrist flexor tendons
31
What is Dupuytren contracture? What is the cause?
Contracture of one or more fingers (usually the ring finger) due to painless thickening and contracture of the tendons of the flexors of the palm
32
What are the risk factors for Dupuytren contracture?
- Family history
- Age \> 40 years
- Male
- Alcoholism
- Smoker
- Diabetes Mellitus
33
What is the treatment for Dupuytren contracture?
Definitive treatment
- Surgical release
Other forms of treatment
- Radiation
- Bacterial collagenase injection
34
What is adhesive capsulitis?
Severe shoulder adhesions that lock the shoulder in place, seen with disuse of the shoulder due to pain or prolonged immobilization
35
What is the treatment for adhesive capsulitis?
Physiotherapy
- Heat
- Analgesia
- Physical therapy to increase range of motion
Medications
- Glenohumeral joint injection
- Subacromial joint injection
Surgery
- Break adhesions under anesthesia (painful!)
36
Name the carpal bones of the hand.
**So Long to Pinky, Here Comes The Thumb!**
Proximal row (Lateral to Medial)
- Scaphoid
- Lunate
- Triquetrum
- Pisiform
Distal row (Medial to Lateral)
- Hamate
- Capitate
- Trapezoid
- Trapezium
37
What condition must one suspect when there is anatomical snuffbox tenderness?
Scaphoid fracture (even if X-ray doesn't show it)
38
What are the side effects of NSAIDs?
- Gastric ulcers
- Acute renal failure from renal ischemia
- Acute interstitial nephritis
- Fluid retention
- Aplastic anemia
39
What are the side effects of aspirin?
- Gastric ulcers and GI bleeding
- Acute renal failure
- Tinnitus
- Hyperventilation
40
What bon disorder results from excess PTH?
Osteitis Fibrosa Cystica
41
What are the diagnostic criteria for systemic lupus syndrome?
Any 4 of the following 11 (MD SOAP BRAIN):
M: Malar rash
D: Discoid rash
S: Serositis - pleuritis, pericarditis
O: Oral ulcers (PAINLESS!)
A: Arthritis (non-erosive, non-destructive, at least involving 2 joints)
P: Photosensitivty
B: Blood - hemolytic anemia, leukocytopenia, lymphocytopenia, thrombocytopenia
R: Renal - lupus (nephritic -- diffuse proliferative glomerulonephritis; nephrotic -- membranous glomerulonephritis)
A: ANA (anti-nuclear antibody) positive
I: Immunological markers - anti-dsDNA Ab, anti-Smith Ab, anti-phospholipid Abs
N: Neurlogical symptoms - seizures, psychosis
42
What are the common causes of death in patients with systemic lupus erythematosus?
- Cardiovascular disease
- Renal disease
- Infections
43
List the immunological markers for SLE and their value in diagnosis and disease management.
ANA: sensitive, very non-specific
Anti-dsDNA antibody: specific, poor prognosis (esp. for renal disease)
Anti-Smith antibody: specific, no known prognostic value
Anti-histone antibody: suggests drug-induced lupus
Anticardiolipin antibody: causes hypercoagulable state
C3, C4 levels: decreased --\> leads to immunosuppression
44
What are the drugs that can cause drug-induced lupus erythematosus?
**SHIPP**
- Sulfonamides
- Hydralazine
- Isoniazid
- Phenytoin
- Procainamide
45
What are the possible causes for a positive ANA result?
- SLE
- Rheumatoid arthritis
- Juvenile idiopathic arthritis
- Polymyositis
- Dermatomyositis
- Scleroderma
- Mixed connective tissue disease
- Sjogren's syndrome
46
What is the main underlying pathophysiology of scleroderma?
Diffuse systemic progressive sclerosis
- Skin tightening with no wrinkles
- Digital pitting
- Distal ulcerations
- Characteristic facies: mask-like face, tight lips, beak nose and radial perioral furrows
47
What are the possible systemic manifestations of scleroderma?
Gastrointestinal
- Dysphagia
- Loss of LES function: GERD, ulcerations and strictures
- Small bowel hypomotility: diarrhea, bloating, cramps, malabsorption, weight loss
- Large bowel hypomotility: **wide mouth diverticuli** on barium study (pathognomonic)
Renal
- Hypertension
- "Scleroderma renal crisis": malignant arterial hypertension, oliguria and microangiopathic hemolytic anemia
Pulmonary
- Interstitial fibrosis
- Pulmonary hypertension
- Pleurisy
- Pleural effusions
Cardiac
- Left ventricular dysfunction
- Pericarditis
- Pericardial effusion
- Arrhythmias
Musculoskeletal
- Polyarthralgias
- Resorption of distal tufts
- Low grade myopathy
Endocrine
- Hypothyroidism
48
What are the two types of scleroderma and what are their characteristics?
_Diffuse scleroderma_
- Rapid progression
- Early systemic involvement
- Widespread skin involvement
- Anti-DNA topoisomerase I/Anti-Scl 70 antibody
_Localized scleroderma (CREST syndrome)_
- Limited skin involvement confined to fingers and face
- C: calcinosis
R: Raynaud's phenomenon
E: Esophageal dysmotility
S: Sclerodactyly
T: Telangiectasia
- More benign clinical course
- Anti-centromere antibody
49
What is the classical presentation of Sjogren's syndrome?
**Can't see, can't spit, can't climb up shit. (Note: Sicca symptoms)**
## Footnote
- Dry eyes: xerophthalmia
\>\> Dryness
\>\> Conjuncitivits
\>\> A feeling of sand in eyes
- Dry mouth: xerostomia
\>\> Dysphagia
\>\> Difficulty in swallowing
- Arthritis
+ Bilateral enlarged parotid glands
+ Dental caries (due to dry mouth)
+ Increased risk for MALT lymphomas
50
List two complications of Sjogren's syndrome.
- Dental caries
- MALT (mucosa-associated lymphoid tissue) lymphoma
51
What are the immunological markers for Sjogren's syndrome?
- Anti-Ro (anti-SS-A) antibody
- Anti-La (anti-SS-B) antibody
- Rheumatoid factor
52
What are the "sicca symptoms"?
- Dry mouth
- Dry eyes
- Nasal dryness
- Vaginal dryness
- Chronic bronchitis
- Reflux esophagitis
Those with sicca symptoms do NOT necessarily have Sjogren's syndrome.
53
What is the mode of inheritance of Duchenne muscular dystrophy?
X-linked
\>\> Frameshift mutation
54
Which protein is affected in Duchenne muscular dystrophy?
Dystrophin protein truncation from DMD gene mutation
- Dystrophin gene DMD has the longest coding region of any human gene
- Dystrophin helps anchor muscle fibres
- Loss of dystrophin results in myonecrosis \>\> accelerated muscle breakdown
55
What is the classical clinical presentation of Duchenne muscular dystrophy?
- Muscle weakness beginning in the pelvic girdle muscles and moving superiorly
- Pseudohypertrophy of calf muscles
\>\> Calf muscles replaced by fibrous fatty tissues
- Gower maneuvre
\>\> Patient rolls from supine to prone
\>\> Uses hands to walk him/herself up
\>\> Hands placed on the knees for support
\>\> Pushes back upright
- Waddling gait
\>\> Onset before 5 years of age
56
What is the most common cause of death in Duchenne muscular dystrophy?
Dilated cardiomyopathy
57
What are some investigations to confirm the diagnosis of Duchenne muscular dystrophy?
- CDK: elevated
- Aldolase: elevated
- Western blot for truncated DMD protein
- Muscle biopsy to visualize muscle fibres and for further investigations
58
What is the normal function of dystrophin?
Helps anchor muscle fibres in skeletal and cardiac muscles
59
What is the difference between the genetic causes of Duchenne and Becker muscular dystrophy?
- Duchenne: X-linked **frameshift** mutation
- Becker: X-linked **point** mutation
\>\> Less severe than Duchenne
\>\> Onset in adolescence or early adulthood
60
What is fibromyalgia?
Excess muscle _tenderness_ in 11 of 18 particular spots
- Low cervical
- Second rib
- Lateral epicondyle
- Knee
- Occiput
- Trapezius
- Supraspinatus
- Gluteus
- Greater trochanter
\>\> Benign course
61
What is the presentation of a patient with fibromyalgia?
- Excess muscle tenderness in at least 11 of 18 particular tender points
- Chronic generalized pain
- Fatigue
- Sleep disturbances
- Headache
- Cognitive difficulty
- Mood disturbances
\>\> 30% have depression and/or anxiety
62
What is the treatment for fibromyalgia?
_Pharmacological treatment_
- Pregabalin: anticonvulsant
- Milnacipran: SNRI
- Amitriptylline: TCA
- Fluoxetine: SSRI
- Low-dose analgesics: NSAIDS, acetaminophen
_Non-pharmacological treatment_
- Reassurance
- Exercise and stretching
- Sleep optimization
- Relaxation techniques
- Stress reduction
63
Anti-Smith Abs and Anti-dsDNA Abs
Systemic lupus erythematosus (SLE)
64
Anti-histone antibodies
Drug-induced lupus
SHIPP:
Sulfonamides
Hydralazine
Isoniazid
Procainamide
Phenytoin
65
Anti-centromere antibodies
CREST (localized) scleroderma
Calcinosis
Raynaud's phenomenon
Esophageal dysmotility
Sclerodactyly
Telangiectasia
66
Anti-Ro antibodies and Anti-La antibodies
Sjogren's syndrome
Anti-Ro = Anti-SSA
Anti La = Anti-SSB
67
Anti-Jo-1 antibodies
Polymyositis
Elevated aldolase
Elevated CPK/CK
Positive ANA
68
Anti-DNA topoisomerase 1 antibody
Diffuse systemic scleroderma
69
What are the layers of the epidermis?
**Californians Like Girls in String Bikinis.**
## Footnote
- Stratum corneum
- Stratum lucidum
- Stratum granulosum
- Stratum spinosum
- Stratum basale
\>\> No blood vessels in the epidermis
\>\> All vasculature in the dermis
70
Name the epithelial cell junction.
- Cadherins
- Connects to actin
- Loss of E-cadherin promotes metastasis
Zonula adherins/Intermediate junction
\>\> Cadherins: Calcium-dependent adhesion proteins
71
Name the epithelial cell junction.
- Claudins
- Occludins
Tight junctions/Zonula occludens
72
Name the epithelial cell junction.
- Intermediate filaments
- Keratin
- Desmoplakin
- Pemphigus vulgaris
Macula adherens/Desmosomes
\>\> Pemphigus vulgaris: anti-desmosome or anti-desmoglein antibodies
73
Name the epithelial cell junction.
- Connexons
Gap junctions
\>\> Cardiac myocytes
74
Name the epithelial cell junction.
- Integrins
- Bullous pemphigoid
Hemidesmosomes
75
What do fibroblasts produce?
- Collagen
- Glycosaminoglycans
- Glycoproteins
- Reticular fibres
- Elastic fibres
76
Where do melanocytes originate from?
Neural crest cells
77
Where do melanocytes reside in?
Stratum basale
78
What is another name for verrucae?
WARTS
79
What is another name for warts?
Verrucae
80
What are the pathological features of warts/verrucae?
- Epidermal hyperplasia
- Hyperkeratosis
- Koilocytes (warts are due to HPV infection)
81
What do you call a wart/verruca in the genital area?
Condyloma acuminatum
82
What is another name for the common mole?
Melanocytic naevus
83
What is another name for a melanocytic nevus?
The Common Mole
84
What is another name for freckles?
Ephelis
85
What is another name for ephilis?
Freckles
86
Which type of hypersenstivity causes allergic contact dermatitis?
Type IV (delayed type) hypersenstivity
## Footnote
- Nickel
- Poison ivy
- Poison oak
- Neomycin
87
What are the four things that create acne?
1. Hyperkeratosis
2. Sebum overproduction
3. Propiobacterium acnes proliferation
4. Inflammation
88
What is the treatment for acne?
Hyperkeratosis
- Vitamin A analogs
- Retinoids (e.g. tretinoin, isotretinoin)
Sebum overproduction
- Isotretinoin
- Spironolactone
- Estrogen (OCPs)
Propiobacterium acnes proliferation
- Erythromycin
- Tetracycline/doxycycline
- Topical clindamycin
- Benzoyl peroxide
Inflammation
- Short term/injectable steroids
\>\> Remember that long-term steroids will *induce* acne -- Cushing's!
89
What is the treatment for psoriasis?
_Topical treatment_
- Emollients and moisturizers
- Steroids
- Tar-containing creams
- Vitamin D analogs
- Retoinoids
- Phototherapy
_Systemic treatment_
- Methotrexate
- Cyclosporin
- Retinoids
90
What are the changes in the epidermal layers in psoriasis?
- Increased stratum spinosum layer
- Decreased stratum granulosm layer
91
What are some histological findings specific to or suggestive of psoriasis?
Overproduction of skin cells
## Footnote
- **Parakeratosis**: nuclei remaining in the stratum corneum layer
- Increased stratum spinosum layer
- Decreased stratum granulosm layer
92
What are some clinical features suggestive of or specific to psoriasis? Name 3.
- Plaques and papules with **silvery scaling**
- _Auspitz sign_: bleeding spots from broken scales/plaques/papules
- _Pitting of the nails_ (similar to a golf ball)
\>\> 1/3rd of patients with psoriasis will have psoriatic arthritis, which is a type of seronegative spondyloarthropathy that is associated with asymmetric and patchy involvement mainly in the fingers (DIP joints -- VS. no DIP joint involvement in RA), spine and sacroiliac joints. Psoriatic arthritis is also associated with _dactylitis_ and the "_pencil in cup_" deformity on X-ray.
93
What are the clinical characteristics of seborrheic keratosis?
- Flat
- Greasy
- Pigmented
- Tortoise-shell like
- Horn cysts
- Looks "_stuck-on_"
\>\> Common _benign_ neoplasm of older people
\>\> Also known as senile warts
94
What is the histological characteristics of seborrheic keratosis?
Squamous epithelial proliferation with _keratin-filled cysts_
95
What is the Leser-Trelat sign?
_Sudden_ appearance of _multiple_ seborrheic keratotic lesions, indicating an *underlying malignancy* (e.g. GI, lymphoid malignancies)
96
What is the underlying pathophysiology of albinism?
A defect/deficiency in tyrosinase
\>\> Normal number of melanocytes
\>\> Decreased melanin production
97
What is the underlying pathophysiology of vitiligo?
Autoimmune destruction of melanocytes
\>\> Irregular areas of complete depigmentation with sharp borders
\>\> A zone with pigmentation only around the follicles (destruction of the perifollicular melanocytes are relatively spared until later) in the transition zone between normal pigmentation and complete depigmentation
98
What is melasma?
Hyperpigmentation associated with:
- Pregnancy
- OCP use
- Hormone replacement therapy
99
Name the lesion.
- Very superficial
- Honey-coloured crusting
- Highly contagious
Impetigo
\>\> Staphylococcus aureus
\>\> Streptococcus pyogenes
\>\> Lips and nose, especially in children
100
Name the lesion.
- Dermis infection
- Acute
- Painful
Cellulitis
\>\> Staphylococcus aureus
\>\> Streptococcus pyogenes
101
Name the lesion.
- Deep tissue injury
- Rapidly spreading
- Extremely tender, even beyond the area of obvious inflammation
- Crepitus upon palpation
Necrotizing fasciitis
- Streptococcus pyogenes
- Anaerobic bacteria (Clostridium perfringes, Vibrio vulnificus)
102
Name the lesion.
- White, painless plaques on the tongue
- Cannot be scraped off
- Associated with EBV infection
- Commonly seen in immunosuppressed individuals (e.g. HIV-positive patients)
Oral hairy leukoplakia
103
What is the treatment for necrotizing fasciitis?
Urgent aggressive surgical debridement with parenteral antibiotics
104
What is the underlying cause of staphylococcal scalded skin syndrome?
Epidermolytic _exotoxin_ A and B of staphylococcus bacteria destroying _keratinocyte attachments_ in the _stratum granulosum_ layer
105
What are the presenting features of staphylococcal scalded skin syndrome (SSSS)?
- Fever
- Generalized erythematous rash
- Sloughing of the upper layers of the epidermis
- Heals completely
\>\> Commonly seen in infants and children
106
What is the underlying pathophysiology of pemphigus vulgaris?
Anti-desmosome or anti-desmoglein antibody (IgG)
\>\> Autoimmune destruction of the desmosomes
107
What are the classical features of pemphigus vulgaris?
DAMN is a vulgar word.
- Desmosomes
- Acantholysis
- Mouth lesions
- Nikolsky's sign positive
\>\> Flaccid intraepidermal bullae caused by acantholysis with _involvement of the oral mucosa_
\>\> Nikolsky's sign: separation of epidermis upon manual stroking of the skin
108
What is the gold standard for diagnosis of pemphigus vulgaris?
Punch biopsy of the skin for direct immunofluorescence: reticular/net-like pattern around epidermal cells
109
What is the underlying pathophysiology of bullous pemphigoid?
IgG antibodies against _hemidesmosomes_
\>\> B for Bullous. B for Basement. B for Bottom.
110
What are the classical features of bullous pemphigoid?
- Less severe than pemphigus vulgaris
- Tense blisters containing _eosinophils_
- Negative Nikolsky's sign
- No involvement of the mouth
111
What is the gold standard for diagnosis of bullous pemphigoid?
Punch biopsy of the skin for direct immunofluoresence, which shows _linear pattern_ at the epidermal-dermal junction
Bu**_ll**_ous pemphigoid for _**l_**inear pattern on I.F.
112
Name the disease.
- Pruritic lesion
- Celiac disease
Dermatitis Herpetiformis
113
Name the lesion.
Erythema multiforme
## Footnote
- Associated with:
\>\> Drugs
\>\> Infections
\>\> Cancers
\>\> Autoimmune disease
- Target-like lesions with multiple rings and dusky centre showing epithelial disruption
114
What drugs can cause Stevens-Johnson Syndrome?
- Anticonvulsants
\>\> Carbamazepine
\>\> Phenytoin
\>\> Ethosuximide
\>\> Lamotrigine
\>\> Phenobarbital
- Sulfa drugs
- Penicillins
- Allopurinol
115
What are the classical features of SJS?
- Fever
- Bulla formation and necrosis
- Sloughing of the skin
- Rash similar to erythema multiforme
- **Involvement of at least 2 mucous membranes**
116
What is the difference between Stevens-Johnson Syndrome and toxic epidermal necrolysis?
Toxic epidermal necrolysis (TEN): when SJS involves _more than 30%_ of the body surface area
117
What conditions is acanthosis nigricans associated with? Name 2.
- Hyperinsulinemia
- Underlying visceral malignancy
118
Which epidermal layer is affected in acanthosis nigricans?
Stratum spinosum
| (Hyperplasia of stratum spinosum)
119
Name the lesion.
- Premalignant to squamous cell carcinoma of the skin
- Sand-paper like on palpation
- Treat with 5-fluorouracil (5-FU)
Actinic keratosis
120
What is erythema nodsum?
Painful inflammatory lesions of subcutaneous fat, usually on the anterior shins
121
What conditions are associated with erythema nodosum?
- Crohn's disease
- Sarcoidosis
- Coccidioidomycoses, histoplasmosis
- Tuberculosis, leprosy
- Group A streptococcus infection
122
Describe the appearance lichen planus.
* *_The 6 Ps of Lichen Planus_**
- Pruritic
- Purple
- Polygonal
- Planar
- Plaques
- Papules
+ Wickham striae (reticular white lines)
+ Sawtooth infiltrate of WBCs in histology at the dermal-epidermal junction
123
What disease is lichen planus related to?
Hepatitis C
124
Name the lesion.
- Herald patches, usually on the trunk and back
- Christmas tree distribution of rash
- Self-limiting within 6-8 weeks
- Helped by sunlight exposure
Pityriasis rosea
125
Name the lesion.
- Rolled edge with central ulceration
- Pearly nodules
- Telangiectasia
- Palisading nuclei
Basal cell carcinoma
126
Name the lesion.
- Keratin pearls
- Actinic keratosis
Squamous cell carcinoma
## Footnote
\>\> Keratoacanthoma: a variant that grows rapidly within 4-6 weeks and may regress spontaneously over months
\>\> Locally invasive
\>\> Rarely metastasizes
127
Name the lesion
- S-100 tumour marker
- Depth correlates to risk of metastasis
Melanoma
128
How does one identify a melanoma?
**_ABCDE _****_for melanoma_**
## Footnote
A: Asymmetry
B: Border irregularity
C: Colour variation
D: Diameter \>6mm
E: Evolution over time
129
What is the most common skin cancer?
Basal cell carcinoma
130
What are the common locations for tophi in a patient with gout?
- External ear
- Olecranon bursa (elbow)
- Achilles tendon
131
What amino acids are commonly found in large concentrations in collagen?
- Glycine
- Proline
- Hydroxyproline
+ Lysine
+ Hydroxylysine
132
What are the steps to collagen synthesis?
1. Synthesis of collagen alpha chains (preprocollagen)
2. Hydroxylation
\>\> Requires vitamin C
\>\> Proline and lysine residues
3. Glycosylation
\>\> Procollagen: triple helix of 3 alpha-collagen chains
\>\> Glycosylation of hydroxylysine residues
\>\> Osteogenesis imperfecta
4. Exocytosis
------------------------------------------------------------------------------------------
5. Proteolytic processing
\>\> Cleavage of disulfide-rich terminal regions
\>\> Tropocollagen (insoluble)
6. Cross-linking
\>\> Covalent lysine-hydroxylysine cross-linkage
\>\> Cu2+-containing lysyl oxidase
\>\> Ehlers-Danlos syndrome
