MSK Flashcards
What are the 3 most common pathogens of septic arthritis?
- Staphylococcus aureus
- Streptococcus penumonia
- Gonococcal infection
Gram negative bacteria usually in immune compromised host with GI infection
Gonnococcal septic arthritis presentation
Can present in 2 ways
- Triad
a) Tenosynovitis
b) Painless vesiculopustular dermatitis
c) Polyarthralgia with prurulent arthritis - Prurulent arthritis without skin lesions
Empiric antibiotic treatment for septic arthritis with culture pending and no results on gram stain
- Vancomycin 15-20 mg/kg IV q 8-12h
- For suspected gonococcal infection Ceftriaxone 1 g IM/IV once daily x 14 days + Azithromycin 1 g PO 1 dose
If immunocompromised, traumatic, IV drug use - add 3rd generation cephalosporin
Antibiotics based on gram stain for gram positive cocci and gram negative bacilli
Gram positive cocci - vancomycin
Gram negative bacilli - 3rd generation cephalosporin (ceftriaxone, ceftazidime, cefotaxime)
Add Gentamycin if pseudomonas is suspected
Gout cystals
Monosodium urate crystals
Negative yellow birifringement needle crystals
Psuedogout crystals
Calcium pyrophosphate dihydrate crystals
Positive blue crystals
Management of gout
Treatment of acute gout
First line - NSAIDs
Second line - Colchicine if within 3 days of acute flare
Third line - Glucocorticoid injection if 1-2 joints, Systemic glucocorticoid for >2 joints
Prophylaxis
First line - Lifestyle modification
Second line - Urate lowering therapy if 3+ attacks/year, radiographic evidence, tophi, renal implications
1. Allopurinol
2. Febuxostat or Probenecid
Start urate lowering therapy with Colchicine or Indomethacin to prevent risk of acute gout flare for the first <6 months
Management of Pseudogout
Treatment of acute gout
First line - rest and immobilization
Medications are the same as gout
Prophylaxis if 3+ attacks per year
First line - Chronic colchicine
Second line - Chronic NSAIDs
Rheumatoid arthritis diagnostic criteria
- Inflammatory arthritis including 3+ joints
- Positive RF or CCP
- Elevated ESR or CRP
- Duration of symptoms >6 weeks
- Other arthritis excluded including spondyloarthropathies, SLE, gout, pseudogout
Rheumatoid arthritis management
1st line - DMARD (+ NSAID or Glucocorticoid until symptoms under control)
Mild - Sulfasalazine or Hydroxychloroquine
Moderate to severe - methotrexate
2nd line - biologics
What are extra articular manifestations that can be seen in rheumatoid arthritis
Sjogren ‘s syndrome
Subcutaneous rheumatoid nodules
Tenosynovitis of hands and feet
Normocytic anemia
Keratoconjunctivitis sicca, episcleritis, scleritis
Interstitial lung disease
Pericarditis
Side effects of NSAIDs
Peptic ulcer and GI bleeding
Hypertension
Renal failure (contraindicated in patients with renal failure or CHF)
Anaphylaxis (contraindicated in asthmatic patients)
Induce labour
Reye’s syndrome
Urate accumulation
Side effects of celecoxibs
Hypertension
Renal failure (contraindicated in patients with renal failure or CHF)
Cardiovascular events (stroke, MI)
Side effects of methotrexate
Nausea, abdo pain, fatigue
Hepatotoxicity
Pneumonitis
Teratogen
Side effects of azathioprine
N/v/d, fatigue, rash
Acute pancreatitis
Increased risk of blood cancer
Side effects of hydroxychloroquine
Nausea, abdo pain
Diarrhea
Blood disorder
Hearing loss
Hepatotoxicity
Muscle weakness/paralysis
Retinopathy **
Side effects sulfasalazine
Infertility
Contraindication to biologics
Positive TB test
Examples of xanthine oxidase inhibitors
Allopurinal
Febuxostat
Examples of uricosuric agents
Probenecid
MOA of xanthine oxidase inhibitors
Inhibit xanthine oxidase which is required in the metabolism of purines to produce uric acid
MOA uricosuric agents
Increase renal excretion of uric acid
Contraindication of uricosuric agents
Renal failure
Xanthine oxidase inhibitor side effects
Nausea, diarrhea
Hepatitis
Hypersensitivity (fever, rash, eosinophilia, Stevens-Johnsons)
Aplastic anemia
Colchicine contraindications
Liver failure
Renal failure
Heart disease
MOA colchicine
Stops microtubule polymerization -> stops mitosis -> stops proliferation of inflammatory cells
Inhibits neutrophil motility and activity
Colchicine side effects
GI upset
Neutropenia
Bone marrow suppression
Poisoning at high doses
Why do you mix glucocorticoid for injection with local anesthetic
Decreases the risk of soft tissue atrophy and tendon rupture
Absolute contraindications to joint injection, soft tissue injection or joint aspiration
Local cellulitis
Septic arthritis
Bacteremia
Acute fracture
Joint prosthesis
History of allergy to injection
Intra-tendinous injection or injection into an area with tendinopathy is contraindicated due to risk of tendon atrophy and weakening
Relative contraindications to joint injection, soft tissue injection or joint aspiraation
Patients with no response after trial of 1-2 joint injections will not likely respond with subsequent injections
Coagulopathy or anticoagulant therapy
Surrounding joint osteoporosis
Anatomically inaccessible joint
Uncontrolled diabetes
Maximum number of glucocorticoid injections
Max 4 injections per year per patient
Back pain red flags
Fracture - history of osteoporosis, history of trauma, history of long term systemic steroid use
Infection - skin opening, history of recent infection, immunocompromised, constitutional symptoms, IV drug use
Malignancy - history of malignancy, constitutional symptoms
Radiculopathy - unrelenting pain at rest and at night
Neurological - weakness, numbness, tingling, cauda equina
Intraabdo/GI/GU - referred pain, dysuria, AAA history
Indications for lumbar xray in low back pain (and ESR if risk of malignancy, infection, inflammation)
Risk factors for cancer (history, suspicion, >50 years, unexplained weight loss)
Risk factors for ankylosing spondylitis (morning stiffness, buttock pain, night pain)
Risk factor for vertebral compression fracture (osteoporosis, glucocorticoid use, trauma, >65 year old man, >75 year old woman)
Signs and symptoms of radiculopathy without bowel or bladder implications
Failing 4-6 weeks of therapy
Indications for MRI in low back pain
risk factor for spinal infection: fever, IV drug use, recent infection
cauda equina syndrome
severe or progressive neurologic deficit
failed 4-6 weeks of therapy with nerve impingement (in L4-S1 distribution, positive straight leg raise), spinal stenosis (radiating leg pain, older age)
MRI may be considered in patients with lower back pain >12 weeks
Indication for referral to neurosurgeon or orthopedic surgeon
cauda equina syndrome
spinal cord compression: acute neurologic deficits in patient with cancer and risk of spinal metastases
progressive or severe neurologic deficit
Indication for referral to neurologist or physiatrist
Motor deficit persisting after 4-6 weeks of therapy
Persistent sciatica, sensory deficit or reflex loss after 4-6 weeks of therapy in patients with positive straight leg raise
Differential diagnosis of chronic low back pain
- Non specific or idiopathic (sprain or strain) 70%
- Mechanical 27%
Degenerative - spondylosis (aka DDD), degenerative disease of facet joints, spinal stenosis
Disk disruption
Fracture - spondololysis, spondololisthesis, osteoporotic
Congenital disease - Non mechanical
Malignancy, infectious, inflammatory, osteochondrosis, Paget - Visceral disease
What is osteochondrosis
Interruption to blood supply to epiphysis causing necrosis and later regrowth
Pharmacological management of low back pain
- Tylenol
- NSAIDs
- Tramadol and opioids
- TCA, gabapentin
- Last line - muscle relaxant
Indications for epidural injection or surgical referral for low back pain
severe functional disability
radiculopathy
refractory pain to non-pharmacological and pharmacological management
Indication for surgery in low back pain
anatomic abnormality identified is consistent with
distribution of pain unremitting pain lasting >1 year despite multiple non-surgical treatment
Features of psoriatic arthritis that differentiate it from rheumatoid arthritis
- Asymmetric involvement of joints
- Involvement of DIP
- Involvement of all joints in one digit
- Dactylitis (inflammation of whole digit including joints and tendons)
- Enthesitis (inflammation of tendon and ligament insertions) such as lateral epicondylitis (tennis elbow) and plantar fasciitis
- Spondylitis
What monitoring has to be performed with methotrexate use
Frequent CBCs due to the risk of bone marrow suppression
Frequent liver enzyme panels due to the risk of hepatitis
Severe potential adverse effect of ace inhibitor
Angioedema
Management of mild eczema
Remission therapy -
Corticosteroid (Desonide, hydrocort, betamethasone) BID x 2-4 weeks in conjunction with emollients
Maintenance
Corticosteroid daily x 2 days during the weekend for up to 16 weeks
Management of moderate eczema
Remission
1st line - Fluocinolone, Triamcinolone, betamethasone same regimen as mild BID x 2-4 weeks in conjunction with emollients
2nd line - topical calcineurin inhibitors BID (Tacrolimus, pimecrolimus)
Maintenance
Desonide, hydrocort, betamethasone daily x 2 days during the weekend x 16 weeks
Management of severe eczema
1st line - phototherapy UVB x 3/week
2nd line - cyclosporine 3-5 mg/kg PO per day in 2 divided doses x 6 weeks for remission and then lowered to minimum effective dose for maintenance up to 1 year
3rd line - DMARD (methotrexate, imuran, cellcept)
What is viral exanthem 1, cause, presentation and infectious period?
Measles (Rubeola)
Cause: Paramyxovirus
Presentation:
Maculopapular erythematous rash following several days following fever
Kopik’s spots (specific for measles)
Fever, cough, coryza, conjunctivitis
Infectious: 3 days before and after rash
What is viral exanthem 2, cause, presentation?
Scarlet fever
Cause: Group A beta hemolytic streptococcus
Presentation: maculopapular sandpaper erythematous rash Strep throat Strawberry tongue Fever
What is viral exanthem 3, cause, presentation?
Rubella (German Measles)
Cause: Togavirus
Presentation: Macular erythematous rash x 3 days with viral symptoms
What is viral exanthem 4?
Filatov-Duke’s disease - historical term not used and does not refer to anything
What is viral exanthem 5, cause, presentation?
Erythema infectiosum (Fifth Disease)
Cause: Parvovirus B19
Presentation: maculopapular erythematous rash usually in cheeks (slapped cheeks) which will then progress to erythematous reticular “lacy” rash to rest of body
What is viral exanthem 6, cause, presentation?
Roseola infantum (exanthem subitum)
Cause: human herpes virus 6
Presentation: high fever, followed by exanthem when child is just about to recover
Hallmark morphology of varicella zoster virus
Simultaneous occurence of all stages of disease including vesicle, pustule and crusts
Pityriasis rosea presentation
Primary herald rash - pink salmon patch with scale and clear centre
Secondary exanthem - generalized pink macules and patches with scale in Christmas tree distribution
RNA enterovirus coxsackie A causes which condition, morphology?
Hand, foot and mouth disease
Painful vesicles around mouth and on extremities, which can blister
Whole infection lasts 7-10 days
Presentation of dermatofibroma
Commonly on arms and legs
Firm hard nodules which can vary in colour
Dimple forms if skin surrounding is squeezed
Indications for wound care
2nd or 3rd intention wound healing
Chronic non-healing wounds
Androgenetic alopecia presentation
Men - M shaped pattern hair thinning (on temples and brow)
Women - thinning in central and frontal scalp with hyperandrogenism signs (PCOS, menstrual abnormalities, hirsutism)
Androgenetic alopecia management
Men
1st line - 5% Minoxidil +/- Finasteride
2nd line - surgery, hair piece
Women
1st line - Minoxidil 2%
2nd line - Spironolactone or cyproterone acetate if no improvement after 1 year of minoxidil
3rd line - hair transplant
Treat hyperandrogenism with hormone replacement or oral contraceptives
Alopecia areata pathophysiology
Autoimmune reaction
Alopecia areata treatment
Mild to moderate <50% scalp involved
1st line - Intralesional corticosteroid injection +/- Minoxidil +/- topical steroids
2nd line - PUVA or corticosteroid
Last line - hair transplant
Severe
1st line - topical immunotherapy (PUVA, topical or systemic corticosteroid)
Minoxidil topical +/0 high potency topical steroids
Hair transplant
Tinea capitis diagnosis
Wood’s lamp fluoresces or slide/culture
Tinea capitis treatment
Oral antifungal
Circatricial alopecia pathophysiology
Repetitive trauma/disorder causes irreversible destruction of hair follicle
Circatricial alopecia treatment
Intra-lesional steroids or antimalarial agents
How long does it take to replace a fingernail or toenail
Finger - 6 months
Toe - 1-1.5 years
Potential causes of longitudinal melanonychia
- Normal variant in black persons
- Subungual melanoma - presents with sudden change in appearance, involves single nail, width >3 mm, extends onto cuticle or nail fold
Onychomycosis cause
Fungal or yeast infection of nail
Onychomycosis diagnosis
KOH testing of scraping or nail culture or biopsy
Onychomycosis treatment
Systemic oral antifungal x 1 year (Terbinafine, itraconazole, fluconazole)
Paronychia cause
Bacterial infection (commonly staph aureus, strep pyogenies or pseudomonas if green)
Paronychia management
Cephalexin
Ketoconazole if fungal infection suspected
Topical neomycin for pseudomonal superinfection
Subungual hematoma management
drilling hole through nail with hot metal wire or co2 laser to relieve pressure
