Autoimmune

Question 1

Fibromyalgia

Answer 1

Idiopathic, chronic, nonarticular widespread pain syndrome
- dx of exclusion*

Sxs:

• widespread msk pain* above/below waist on both sides >3 mo, radiating diffusely +/- arthralgia
• external stressors
• allodynia, fatigue, HA, IBS, insomnia, functional impairment

Dx: CBC, ESR, CRP, TSH, ANA, RF, Xray

Tx:

• pt ed: chronic, not progressive, not curable
• treat comorbidities: weight loss, mood, sleep
• exercise
• ADs: amitriptyline, duloxetine
• analgesics: tramadol, APAP, cyclobenzaprine

Question 2

Gout General

Answer 2

Deposition of uric acid crystals throughout body
- MC acute monoarthritis

Hyperuricemia d/t:

• dec excretion (hereditary, diuretic, ETOH, renal disease, cyclosporine)
• inc production
• inc intake

Triggers: ETOH, trauma, diuretics, salicylates, allopurinol, contrast dye

Sxs:

• asx hyperuricemia 10-30y
• acute/intermittent gout: rapid onset exquisite pain a/w warmth, swelling, erythema; pain Inc over 8-12hr; +/- fever, chills
• intercritical period: asx period after flare w/crystals still forming
• chronic tophaceous gout: usually 10+ yr after onset; intercritical periods no longer pain free

Question 3

Gout Dx/Tx

Answer 3

Dx

• hyperuricemia w/serum uric acid >7mg/dl (may be normal)
• CBC: leukocytosis w/Inc PMNs
• ESR/CRP: may be elevated
• definitive**: synovial fluid arthrocentesis - monosodium urate crystals under polarized light microscope
• GS/Cx r/o infection

Tx

• acute: NSAIDs until 1-2d after sx resolve [> colchicine > steroids]
• resolution, then maintenance: uric acid lowering tx + NSAID/colchicine

Uric acid lowering

• Xanthine oxidase inhibitor: allopurinol; if renal function good
• Uricase: pegloticase

Start maintenance if >2 attacks/yr, tophi present, urolithiasis

Comorbid disease: diet, ETOH, obesity

Question 4

Pseudogout

Answer 4

• calcium pyrophosphate crystal deposition *
• intermittent monoarthritis in knee/wrist

Sxs:

• acute, monoarticular inflammatory arthritis lasting days-wks (50% knees)
• asx between episodes
• provoked by illness, trauma, surgery
• may cause progressive DJD, valgus deformity of knees, patellofemoral arthritis

Dx:

• synovial fluid analysis to differentiate from gout
• CPPD crystals**
• ESR/CRP may be elevated

Tx:

• same as gout
• colchicine daily useful for px, but doesn’t work as well compared to as with gout
• tx concurrent metabolic conditions

Question 5

Polymyositis

Answer 5

MC 10-15y and 45-60y; women

Sxs: inflammatory myopathy + prox muscle weakness*

• interstitial fibrosis or pneumonitis (record baseline pulm fx, CXR)
• cardiomyopathy or CHF

Dx: Bx = T-cell mediated lymphocytic infiltrates*

• INC CK, aldolase, LDH
• EMG changes
• MRI: delineate muscle involvement to guide biopsy

Tx:

• prednisone taper 3-6mo
• MTX, AZA

Question 6

Reactive arthritis (Reiter syndrome)

Answer 6

“can’t see, can’t pee, can’t climb a tree”
- spondyloarthritis following infection

Urethritis bugs: Chlamydia, Yersinia, Salmonella, Shigella, Campy, C. diff

Sxs:

• asymmetrical mono/oligo arthritis in LE
• enthesistis/dactylitis
• GU sx
• conjunctivitis, oral ulcers, rashes, nail changes, genital lesions

Dx:

• stool testing, chlamydia screening, HLA-B27, ESR/CRP, WBC
• imaging to r/o OA

Tx:

• NSAIDs
• glucocorticoids
• Abx for acute infection

Question 7

Rheumatoid arthritis

Answer 7

Inc r/o MI, CVA, infection, NHL, osteoporosis

Sxs:

• symmetric joint pain, stiffness, swelling
• morning stiffness >1hr
• systemic symptoms
• other: synovitis, effusion, erythema, warmth, decreased ROM

Dx:

• positive RF, anti-CCP
• JFA: inflammatory
• Xray: eval for erosive changes

Tx:
- DMARDs: plaquenil, MTX, Leflunimide, sulfasalazine, AZA
[DMARDs require monitoring for: BM suppression, renal insufficiency and function]
- adjunct: NSAIDs, steroids

Question 8

Systemic lupus erythematous General

Answer 8

Vascular: accelerated atherosclerosis = TIA, CVA, MI

May be drug induced - hydralazine

Manifestations

• skin: malar or discoid rash, oral/nasal ulcers; nonscarring alopecia, diffuse thinning
• synovitis in 2 joints or tenderness in 2 joints + 30 min morning stiffness
• serositis (lung or pericarditis)
• renal: nephritis, proteinuria, RBC cases, hematuria
• neuro: seizure, psychosis, mononeuritis multiplex
• hemolytic anemia

Question 9

SLE dx/tx

Answer 9

Dx

• U/A: investigate nephritis
• leukopenia, lymphopenia
• ANA
• Anti-dsDNA, anti-Sm, APL-ab, low C’
• check LDH, haptoglobin, Coombs (hemolytic anemia)
• Pregnancy: monitor APS (anti-coagulation), SSA/SSB
• if SSA+, monitor baby for heart block between 18-24wk in utero

Tx:

• steroids for skin lesions
• aggressive mgmt of HLD, HTN, hyperglycemia (protect renal)
• non-lifethreatening: NSAIDs, low dose corticosteroid, hydroxychloroquil, MTX, mycophenolate, AZA
• organ involvement: prednisone, IV methylprednisolone, DMARDs, etc.
• SLE/preg: control sxs w/low dose prednisone, plaquenil, AZA

Question 10

Lupus nephritis

Answer 10

Class II: microscopic hematuria, proteinuria

Class III: + HTN, dec GFR, +/- nephrotic syndrome; <50% of glomeruli affected

Class IV: MC and severe**

• • low C’
• elevated dsDNA levels w/active disease
• > 50% glomeruli affected

Class V: diffuse thickening of glomerular capillary wall and subepithelial immune deposits

Tx:

• induction: glucocorticoids & cyclophosphamide OR mycophenolate mofetil
• maintenance: AZA OR mycophenolate mofetil