Arthritis

Question 1

Early RA

Answer 1

Type III hypersensitivity reaction (immune complex mediated)

Women

IgM Ab against IgG - Rhematoid factor - low specificity
Anti-citrullinated protein Ab (ACPA) aka anti CCP - more specific

Moring stiffness - improves with use

Symmetric joint involvement

Systemic sx: fever, fatigue, pleural effusion, pericarditis

Question 2

Acute treatment of RA

Answer 2

Acute: NSAIDs, COX2 inhibitor, steroids

Question 3

Long term treatment of RA

Answer 3

DMARDs: 
low dose methotrexate
Hydroxychloroquine
Sulfasalazine
TNF alpha inhibitors: Etanercept, infliximab, adalimumab, golimumab, certolizumab

Question 4

Acute gout treatment

Answer 4

1. NSAIDs - indomethacin tx of choice
2. Colchicine - low doses - caution low therapeutic index
   -binds to and stabilizes tubular, inhibiting polymerization
   -impairs leukocyte chemotaxis - decrease inflammation
   SE: diarrhea

Prednisone

Question 5

Chronic gout treatment

Answer 5

Probenecid:
increases renal excretion of uric acid
inhibits reabsorption of uric acid in PCT
Caution: inhibits secretion of PCN

Allopurinol and febuxostat:
decrease uric acid synthesis
inhibits xanthine oxidase

Question 6

Pseudogout

Answer 6

Calcium pyrophosphate crystals - rhomboid shaped and positively (blue) birefringent

affects large joint - classically knee, in older patients

XR: chonedrocalcinosis - articular cartilage, esp meniscus

Question 7

Seronegative spondyloarthropathies

Answer 7

“PAIR” - Psoriatic arthritis, Ankylosing spondylitis, IBD spondylitis, Reactive arthritis

Negative RF
HLA B27

Tx: TNF alpha inhibitor, risk reactivation of TB, check ppd

Question 8

TNF alpha inhibitors used in seronegative spondyloarthropathies

Answer 8

etanercept - decoy receptor
Infliximab
Adalimumab
Golimumab
Certolizumab

prevent immune system activation
Risk of reactivating TB, check PPD before administering

Question 9

Psoriatic arthritis

Answer 9

Inflammatory arthritis assoc w/ psoriasis

Asymmetric arthritis in fingers, DIP joints, spin and/or SI joints
Dactylics - sausage fingers

XR: pencil in cup deformity

Question 10

Ankylosing spondylitis

Answer 10

20s-30s
Spine and SI joints

Reduced spine motility, improves w/ exercise
XR: bamboo spine

uveitis

increased risk of CV disease: aortic regurg, conduction abnormalities, PVD, CHF

Question 11

Reactive arthritis

Answer 11

“Can’t see, can’t pee, can’t climb a tree”

Typically Chlamydia or GI infections (Shigella, Salmonella, yersinia, Campylobacter, Clostridium)

Conjunctivitis, Urethritis, arthritis

Question 12

Juvenile idiopathic arthritis (JIA)

Answer 12

before 10 yo

persistent joint swelling - synovial thickening, accumulation of synovial fluid

Question 13

Subtypes of Juvenile idiopathic arthritis

Answer 13

Polyarticular JIA: severe symmetrical arthritis, dactylics

Pauciarticular JIA: typically large joints (almost never starts in hips), 20-25% have uveitis

Systemic onset JIA: Still’s dz: begins with systemic sx - fever, rash, elevated WBC, anemia, HSM, LAD - like leukemia to start
-arthritis later

Question 14

Infectious (septic) arthritis

Answer 14

S. aurea, streptococcus
N. gonorrhoeae - migratory polyarthritis, asymmetrical, involves knee

Dx: arthrocentesis - WBCs, bacteria

Tx: IV abx, needle joint aspiration or surgical joint drainage