Day 8.3 MSK/Derm Flashcards
What are the seronegative spondylo-arthropathies?
Arthritis w/o RF (sero-negative- so no anti-IgG Ab).
Strongly a/w HLA-B27 (which codes for MHC-I). More common in males.
Ankylosing spondylitis
Reactive arthritis (Reiter’s)
Psoriatic arthritis
Ankylosing spondylitis
Chronic inflam dz of spine and sacroiliac joints leads to ankylosis (stiff spine dt joint fusion), uveitis, and aortic regurg.
Stiffness improves w (or requires) exercise
Sacroiliitis = think ank spond!
Bamboo spine - IV discs outlined by calcifications.
Reactive arthritis (Reiter’s)
Classic triad: 1. Conjunctivitis and anterior uveitis 2. Urethritis 3. Arthritis Can't see, pee, climb a tree Often post-GI (shigella flexneri) or post-Chlamydia infection
Psoriatic arthritis
Joint pain and stiffness a/w psoriasis. Asymmetric and patchy involvement. Dactylitis (sausage fingers) Pencil in cup deformity on xray. Seen in fewer than 1/3 of pts w psoriasis
Rx for seronegative spondyloarthropathies
Anti-TNFa agents: Etanercept, Infliximab, Adalimumab
also NSAIDs and steroids can be used.
SLE lab results
ANA+ (anit-nuclear Ab. good screening test, but not specific for SLE)
Anti-dsDNA Ab (esp for renal dz. poor pgx)
Anti-Smith Ab
Anti-histone Ab (for drug-induced)
Also, will have false-pos VRDL for syphilis dt anti-phospholipid Ab, which cross-react w cardiolipin (aka anti-cardiolipin Ab)
SLE epi and sx
Black Female, 14-45 yo Fever, fatigue, weight loss non-bacterial verrucous endocarditis hilar adenopathy Raynaud's Wire-loop lesions in kidney w immune complex deposition (usu nephritic syndr) Death from renal failure and infections.
Causes of drug-induced SLE
SHIPP: Sulfonamides Hydralazine INH Phenytoin Procainamide
SLE: I’M DAMN SHARP sx
Immunglobulins (anti-dsDNA, anti-Sm, antiphospholipid)
Malar rash
Discoid rash
ANA+
Mucositis (oropharyngeal ulcers)
Neurologic disorders (seizure, psychosis)
Serositis (pleuritis, pericarditis) Hematologic disorders (anemia, leukopenia, lymphopenia, thrombocytopenia) Arthritis Renal disorders Photosens
Things that can give ANA+
SLE Sjorgren's (and sicca) Scleroderma Polymyositis Dermatomyositis RA Juvenile arthritis MCTD
Rx for SLE
Glucocorticoids
NSAIDs
Hydroxy-chloroquine (anti-malarial)
Cyclophosphamide
Sarcoidosis
Immune-mediated non-caseating granulomas that are widespread, plus elevated serum ACE levels.
Common in black females.
A/w GRAIN: Gammaglobulinemia Rheum arthritis ACE increase Interstitial fibrosis Non-caseating granulomas and Restrictive lung dz Bilateral hilar lymphadenopathy Erythema nodosum Bell's palsy epithelial granulomas containing Schaumann and asteroid bodies Uveopartotitis Hyper-calcemia (d.t elevated Vit D, which is converted a lot to its active form in epitheloid macrophages.
Rx: Steroids
What is erythema nodosum?
Painful, nodular inflam of subcutaneous fat, classically on the anterior shin (in front of tibia)
Seen in sarcoidosis
What is polymyalgia rheumatica?
Pain/stiffness in shoulders and hips, often w fever, malaise, weight loss.
Despite the name myalgia, it does NOT cause muscular weakness.
Occurs in pts >50yo
A/w temporal (giant cell) arteritis
Findings: elevated ESR and normal CK (aka CPK), a marker for muscle cell breakdown
Rx: Prednisone (steroids)
What are the findings and Rx for polymyositis and dermatomyositis?
Increased CK, increased aldolase
Positive ANA
Anti-Jo1 Ab
Rx: steroids
Polymyositis
progressive symmetrical proximal musc weakness caused by CD8+ T-cell induced injury to myofibers.
Most often involves shoulders (and pelvis)- most musc dz affects proximal musc, whereas nerve dz affects distal.
Dx by musc biopsy showing evidence of inflam
Dermatomyositis
Like polymyositis (symm proximal musc weakness d.t CD8+ injury to myofibers) But also involves malar rash, heliotrope rash (around eyes), shawl-and-face rash, Gottron's papules, mechanic's hands. Increased risk of malignancy (the normal neoplasms- lung, breast, etc)
Myasthenia Gravis
Most common NMJ disorder.
Auto-Ab to the post-synaptic ACh receptor
Causes ptosis, diplopia, general weakness
A/w thymoma
Sx get worse (!) w musc use
Rx: AChE inhibitors (cause ACh to stay around longer)
Lambert-Eaton syndrome
NMJ dz
Auto-Ab to presynaptic Ca2+ channel, results in decreased ACh release, so proximal musc weakness.
Unlike MG, extraocular musc are spared.
Assc w paraneoplastic dz (sml cell lung cancer)
Sx improve w musc use (test: isometric contraction improves musc strength)
No reversal of sx w AChE inhibtors alone.
So: dry mouth + impotence + muscle weakness, and assoc w sml cell lung carcinoma = lamb-eaton
Mixed CT Dz
Raynaud's FAME: Raynaud's Fatigue Arthralgias Myalgias Esophageal hypomotility
Ab to U1RNP
Responds to steroids
Scleroderma
aka PSS- progressive systemic sclerosis
Excessive fibrosis and collagen deposits thru-out body.
Commonly in skin- puffy taut skin w no wrinkles
There is also sclerosis of renal, pulm, CV, and GI systems
75% female.
“bulking” dz
2 types= diffuse and CREST
Diffuse scleroderma
widespread skin involvement, rapid progression, early visceral involvement.
Anti-Scl-70 Ab (aka Anti- DNA topoisomerase I Ab)
CREST scleroderma
CREST: Calcinosis (subepithelial Ca2+ deposits) Raynaud's Esophageal dysmotility Sclerodactyly (sausage fingers) Telangiectasia
Limited skin involvement- confined to fingers and face.
More benign than diffuse.
Anti-Centromere Ab
Lipoma
Benign
Soft, well-encapsulated fat tumor
Cure by simple excision
Liposarcoma
Malignant fat tumor; can be very lg.
Will recur unless absolutely all of it is removed
Rhabdomyoma
Benign tumor derived from striated musc (either skeletal or cardiac)
Cardiac rhabdomyoma is common in tuberous sclerosis
Rhabdomyosarcoma
Malignant
Most common soft tsu tumor of childhood
Arises from skel musc, most often in head/neck
Derm:
Macule
Patch
Both macules and patches are flat lesions
Macule - flat discoloration 1cm
Ex: tinea versicolor
Derm:
Papule
Plaque
Both papules and plaques are elevated lesions
Papule - elevated and 1cm
Papule: acne vulagris
Plaque: psoriasis
Derm:
Vesicle
Wheal
Bulla
These are blisters
Vesicle- sml fluid containing blister (chickenpox)
Wheal - transient vesicle (hives)
Bulla - lg fluid containing blister (bullous pemphigoid)
Derm: Keloid
Irregular raised lesion resulting from scar tsu hypertrophy.
Follows trauma to skin, esp in african americans.
Basically just excess collagen- too much scarring.
Often on upper chest, ear lobe.
Ex: T. perenue (yaws)
Rx inject local steroids
Derm:
Pustule
Crust
Pustule - blister containing pus (impetigo)
Crust- dried exudate from a vesicle, bulla, or pustule
Derm:
Hyperkeratosis
Parakeratosis
Hyperkeratosis: increased thickness of the stratum corneum (psoriasis)
Parakeratosis: hyperkeratosis w retention of nuclei in the stratum corneum (also psoriasis)
Derm:
Acantholysis
Acanthosis
Acantholysis: separation of epidermal cells (pemphigus vulgaris)
Acanthosis: epidermal hyperplasia d/t increased spinosum layer (acanthosis nigricans)
Dermatitis
Inflam of the skin
Skin disorders: Verrucae
Warts
Soft tan cauliflower-like lesions
Epidermal hyperplasia, hyperkeratosis, koilocytosis
Verucca vulgaris on hands
Condyloma acuminatum on genitals (caused by HPV)
Skin disorders: Nevocellular nevus
common mole. benign
Skin disorders: Uticara
Hives
Intensely pruritic wheals that form after mast cell degeneration
Skin disorders: Ephelis
Freckle.
Normal number of melanocytes, but increased melanin pigment
Skin disorders: atopic dermatitis (aka eczema)
Pruritic eruption, commonly on skin flexures (eg anticubital fossa of knee)
Often a/w other atopic dz (asthma, allergic rhinitis)
Common px: kids <1yo getting bathed too frequently.
Skin disorders: allergic contact dermatitis
Type IV HPS
Follows exposure to allergen- eg nickel, poison ivy
Lesions occur at site of contact
Skin disorders: psoriasis
Papules and plaques (elevated) w silvery scaling (!), esp on knees and elbows.
Acanthosis (spinosum hyperplasia) with parakeratotic scaling (nuclei still in stratum corneum)
Increased stratum spinosum, decreased stratum granulosum
Auspitz sign: bleeding spots when scales are scraped off
Can be a/w nait pitting and psoriatic arthritis
Skin disorders: Seborrheic keratosis
Flat, greasy, pigmented sq epithelial proliferation w keratin-filled cysts (horn cysts).
Looked “pasted on”
Lesions on head, trunk, extremities
Common benign neoplasm of ELDERLY (young ppl get moles, old ppl get seborrheic keratosis)
Sign of Leser-Trelat: sudden appearance of multiple seborrheic keratoses, indicating an underlying malignancy (eg GI lymphoid)
Pigment disorders: albinism
Normal melanocyte number, but decreased melanin production d/t decreased activity of tyrosinase. (melanin is made from tyrosine).
Can also be caused by failure of neural crest cell migration during devt
Pigment disorders: vitiligo
Irregular areas of complete depigmentation
Caused by decreased number of melanocytes
Pigment disorders: melasma
Hyperpigmentation a/w pregnancy (mask of pregnancy) or with OCP use
Infectious disorders: impetigo
V superficial skin infection
Usu from S. aureus or S. pyogenes
Highly contagious
Honey-colored crusting around lips/mouth
Infectious disorders: Cellulitis
Acute, painful spreading infection of dermis and subcutaneous tsu.
Usu from S. pyogenes or S. aureus
Infectious disorders: Necrotizing fasciitis
Deep tsu injury, usu from anaerobic bacteria or from S. pyogenes.
Results in crepitus (popping) from methane and CO2 production
Flesh-eating bacteria
Infectious disorders: SSSS staphylococcal scalded skin syndrome
Staph exotoxin destroys keratinocyte attachments in the stratum granulosum (only).
Px w cough, fever, generalized erythematous rash, and sloughing off of upper layers of epidermis
See in newborns and children
Infectious disorders: Oral Hairy Leukoplakia
White painless plaques on tongue that CANNOT be scraped off.
Caused by EBV
Occurs in HIV+ pts
Blistering disorders: Pemphigus vulgaris
Auto-immune: IgG Ab against desmosomes (which connect cells to cells)
aka anti-epithelial cell Ab, anti-desmoglian Ab
Can be fatal.
Immunoflurescence: Ab around cells of epidermis in reticular/netlike pattern
Acantholysis: intraepidermal bullae involving skin and oral mucosa (diagnostic)
Positive Nikolsky’s sign- separation of epidermis upon manual stroking of skin
Blistering disorders: Bullous pemphigoid
Auto-immune. IgG Ab against hemidesmosomes (connect cell to BM).
Ab are “bullow” (below) the epidermis
Shows linear immunofluorescence.
Eosinophils w/in blisters.
Similar but less severe than pemphigus vulgaris- affects skin, but spares oral mucosa, and there is a negative Nikolsky’s sign (epidermis doesn’t separate on stroking)
Blistering disorders: Dermatitis herpetiformis
Pruritic papules and vesicles
Deposits of IgA at tips of dermal papillae
A/w celiac dz
Blistering disorders; Erythma multiforme
A/w infections (mycoplasma pneumoniae, HSV) and esp w drug rxns- sulfa, B-lactams, phenytoin. Also assoc w cancer and auto-imm dz.
Px: multiple types of lesions- macules, papules, vesicles, target lesions (pale center)
Blistering disorders; Stevens-Johnson Syndrome
Fever, bulla formation (bulla- lg fluid blister), and necrosis, with sloughing of skin.
High mortality rate.
Usu a/w adverse drug rxn
More severe form: TEN toxic epidermal necrolysis. >30% of body area is sloughing off and detaching.
Caused by seizure meds, sulfa, -cillins, allopurinol
Misc skin: Lichen planus
PPPP: pruritic, purple, polygonal papules
Sawtooth infiltrate of lymphocytes at dermal/epidermal jn.
Assoc w HCV
Misc skin: Actinic keratosis
Pre-malignant lesions caused by sun exposure.
Small rough sandpapery erythematous or brownish papules. “Cutaneous horn”
Risk of carcinoma is proportional to epithelial dysplasia.
Rx: 5-FU turns it beefy red
Misc skin: Acanthosis nigricans
Hyperplasia of stratum spinosum.
A.w hyperinsulinemia (cushings dz, diabetes)
if >40 w new acanthosis nigricans- visceral malignancy.
Msic skin: Erythema nodosum
Inflammatory lesions of subcutaneous fat, usu on anterior shins
A/w cocci, histoplasmosis, TB, leprosy, strep infections, sarcoidosis
Misc skin: Pityriasis rosea
“Herald patch” on trunk/back followed days later by “xmas tree” distribution.
Multiple papular eruptions, remits spontaneously. Benign.
Misc skin: Strawberry hemangioma vs Cherry hemanigoma
Strawberry: first few weeks of life, grows rapidly and regresses spontaneously at 5-8 yo.
Cherry- appears in 30s-40s, does not regress.
4 causes of acne
Hyperkeratosis
Sebum overproduction
Proliferation of Proprionibacterium acnes
Inflammation
How to treat acne
Proliferation of P. acnes: Benzol peroxide (1st line), erythromycin, tetracycline, topical clindamycin, sulfacetamide
Sebum overproduction: isotretinoin, spironolactone (anti-androgen), estrogens
Hyperkeratosis: Vitamin A analogs, topical retinoic acid, isotretinoin
Inflam: short term local steroid injection at lvl of lesion
Skin rash + proximal muscle weakness
Dermatomyocytis
Most common skin cancers
- Basal cell carcinoma
- Sq cell carcinoma
- Melanoma
List skin cancers in order of metastatic potential:
- melanoma (worst)
- sq cell carcinoma
- basal cell carcinoma
Melanoma
Skin cancer w high risk of metastasis
Dark w irreg borders.
S-100 tumor marker
a/w sunlight exposure, fair-skinned pts at incrsd risk
Depth of tumor correlates w risk of metastasis
ABCD:
Asymmetry, Border irreg, Color (diff colors w/in same lesion), Diameter (bigger than pencil eraser)
What is a precursor to melanoma?
Dysplastic nevus (atypical mole)
Basal cell carcinoma
Most common skin cancer.
Locally invasive, but usu never metastasizes.
Rolled edges w central ulceration.
Histo: palisading nuclei (nuclei line up long-ways)
Gross: pearly papules, commonly w telangiectasias
Squamous cell carcinoma
2nd most common skin cancer after basal cell.
A/w excessive sunlight and arsenic exposure.
Common on hands/face
Locally invasive, rarely metastasizes.
Ulcerative red lesion- erosive.
A/w chronic draining sinuses.
Histo: keratin pearls
Precursor to sq cell carcinoma
Actinic keratosis (sandpaper lesion)
Keratoacanthoma
variant of sq cell carcinoma that grows rapidly (4-6wks) and regresses spontaneously (4-8wks)
Dome-shaped, wartlike.
Mech of Aspirin
Irreversibly (!!) inhibits COX-1 and COX-2 by covalent binding, which causes less TXA2 and prostaglandins to be produced.
Aspirin clinical use
Low dose (<300mg/day): decreases plt aggregation Med dose (300-2400mg/day): antipyretic and analgesic High dose (2400-4000 mg/day): anti-inflam
Toxicity of aspirin
Gastric upset
Chronic use can lead to acute renal failure, interstitial nephritis, and upper GI bleeding.
Reye’s syndrome in kids w viral infection.
Acetominophen mechanism
Reversibly inhibits COX, mostly in CNS. Inactivated peripherally.
Acetominophen clinical use
anti-pyretic, analgesic, but does not have anti-inflam properties.
use instead of aspirin in kids w viruses so they don’t get reye’s
Acetominophen toxicity
overdose causes hepatic necrosis
acetaminophen metabolite depletes glutathione and forms toxic tsu adducts in the liver.
What is the antidote to acetaminophen OD?
N-acetylcysteine (it regenerates glutathione)
What is N-acetylcysteine used for?
Antidote for acetaminophen OD
Prevents contrast-induced nephropathy
Mucolytic (breaks up mucous plugs, eg in CF, bronchial asthma)
What is fibromyalgia?
Excess muscular tenderness in 11/18 sites
Chronic generalized pain, fatigue, sleep disturbances, HA, cognitive difficulty, mood disturbances (30% have deprsn/anx)
Rx for fibromyalgia
Pregabalin, milnacipran (SNRI)
Amitryptiline (helps to sleep), low-dose analgesic, fluoxetine
Reassurance, exercise.stretching, sleep, relaxation techniques, stress reduction
What skin disorder has pruritic, purple, polygonal papules?
Lichen planus
What skin disorder has life threatening rash w bulla?
Stevens-Johnson Syndrome (and TEN)
Pemphigus vulgaris
What skin disorders consists of pruritis a/w asthma?
Eczema (atopic dermatitis)
What skin disorder has pruritic veslcles and is a.w celiac dz?
Dermatitis herpetiformis
What skin disorder exhibits an allergy to nickel?
Contact dermatits (type IV HPS)
What skin disorder results in a thickened scar esp around face.chest?
Keloids
What skin disorder has Ab against epidermal BMs?
Bullous pemphigoid (Ab against hemidesmosomes)
What skin disorder has Ab against epidermal cell surface?
Pemphigus vularis (Ab against desmosomes)
What skin disorder exhibits parakeratotic scaling?
Psoriasis
What skin disorder has keratin-filled cysts?
Seborrhic keratosis (in old pts)
What skin disorder is characterized by sand paper lesions and predisposes to sq cell cancer?
Actinic keratosis
What skin disorder exhibits skin rash w proximal musc weakness?
Dermatomyositis
What skin disorder features honey-crusting lesions common around the nose/lips?
Impetigo
What skin disorder exhibits hyperderatosis and koilocytosis?
Verruca (warts- from HPV)
What skin disorder shows palisading nuclei on histology?
Basal cell carcinoma
