Arthrocentesis General Concepts Indication for Joint Aspiration: Presence of an effusion in a single joint with unclear etiology Symptomatic relief in a patient with a known arthritic condition Monitor therapeutic response in a patient with infectious arthritis Indication for Joint Injection: Suppression of inflammation for up to a few peripheral joints once infection is ruled out As much fluid as possible should be aspirated before intra-articular glucocorticoid therapy Steroid injection works in 1-7 days, benefit may last weeks to 1 yr. Contraindication to Joint Aspiration and Injection:
Gonococcal Bacterial Arthritis Predisposing factors: Young, sexually active H/o complement deficiency Clinical: Migratory polyarthralgia Fever Tenosynovitis Dermatitis 80% with asymptomatic gonococcal STD infection. Treatment: Ceftriaxone 1g IV qday.
Nongonococcal Bacterial Arthritis Etiology: Hematogenous spread (~70%) Bite/trauma Direct inoculation or contiguous spread from adjacent to the joint Underlying arthritis Predisposing factors: Immunosuppression Intravenous drug use Indwelling catheters Neonates Elderly Infective endocarditis Prosthetic joints Microbiology: Staphylococcus aureus (most common in adults) Staphylococcus epidermidis (post-op, prosthesis) Streptococci (2nd most common, splenic dysfunction) Gram-negative bacilli (IVDU, neonates, elderly, DM, immunosuppressed, sickle cell) Clinical: Acute onset monoarticular arthritis (80%) Knee (>50%), wrist, ankles, hips Can be oligoarticular or polyarticular, usually in the setting of rheumatoid arthritis, connective tissue diseases, or sepsis Fever is common Associated skin, urine, or respiratory tract infection may be present Diagnosis:
Labs: leukocytosis with left shift, blood cultures (+ in 50% of cases).
Radiographs: usually normal at presentation but useful to rule out concurrent osteomyelitis or joint disease
CT/MRI: useful to detect effusions/inflammation in hip and spine Differential Diagnosis: Crystal-induced arthritis Reactive arthritis Rheumatoid arthritis Lyme disease Mycobacterial arthritis Psoriatic arthritis Treatment:
Intravenous antibiotics: Initially can base choice on gram stain or likely organism given history
Gram-positive cocci: vancomycin
Gram-negative rods: 3rd generation cephalosporin
Joint drainage: Notify orthopedics immediately as they may want to clean out the joint in the OR Other option is daily aspiration (need to see improving WBC count in synovial fluid)
Crystal Deposition Arthritides Gout
Definition: a term for clinical syndromes of urate crystal deposition disease: Acute inflammatory arthritis Tophaceous deposits Uric acid nephrolithiasis Uric acid nephropathy
Acute gouty arthritis: Predisposing factors: any acute change in the uric acid concentration (i.e. diuretics, allopurinol, excess alcohol consumption, diet, surgery) Clinical features: Severe pain, erythema, swelling 80% of initial attacks are monoarticular, typically in the lower extremities Most often at first metatarsophalangeal joint (i.e. podagra) with inflammation often extending beyond involved joint Fever, leukocytosis, and inc ESR can occur (difficult to distinguish from acute septic arthritis) Diagnosis: At least 10% have normal uric acid levels. Joint aspiration of synovial fluid shows: Needle-shaped, negatively birefringent crystals (intracellular monosodium urate) under polarized light microscopy Sensitivity > 85%, specificity ~100% WBC 3000-50,000 (>50% polymorphonuclear cells) Note that gout and septic arthritis can coexist, so always also a check gram stain and culture! Treatment: Anti-inflammatory therapy
NSAIDs: 1st line (depending on renal function) Indomethacin 150 mg p.o. daily (divided b.i.d. or t.i.d.) usually for 7-10 days Reduce dose by half as soon as clinical improvement to reduce risk of GI intolerance If longer course of treatment needed, consider alternative NSAID +/- PPI Glucocorticoids (intraarticular or orally)
Intraarticular: option if few inflamed joints (must rule out infection first!)
Systemic: for patients who cannot take NSAIDs, COX-2 inhibitors, or colchicine and who are not candidates for intraarticular injection. Consider oral prednisone versus intravenous methylprednisolone Colchicine (orally only, do not give intravenously!) Effective especially when stared early Main side effects are GI: nausea, vomiting, diarrhea Must reduce dose in hepatic or renal disease (risk of bone marrow suppression) Dose at 0.6 mg/hr orally until relief of symptoms OR total daily dose of 6 mg reached OR adverse effects limits use Once symptoms are improving, can reduce dose to 0.6 mg orally b.i.d. until resolution Allopurinol Do not start if acute gout attack. Dose 100mg po daily, raise weekly to desired dose. Treatment options for special cases
Hospitalized patients who are NPO: intravenous or intraarticular glucocorticoids
Decreased GFR: glucocorticoids (avoid colchicine and NSAIDs)
Renal transplant patients: defer to renal transplant team Pseudogout (calcium pyrophosphate dihydrate deposition disease)
Definition: acute self-limited synovitis induced by calcium pyrophosphate dihydrate deposition
Clinical features: resembles gout, acute to subacute monoarticular or pauciarticular arthritis Typically located in the knees (>50%), wrists, and/or metatarsophalangeal (MTP) joints
Etiologies: trauma, surgery, severe illness (similar to gout)
Diagnosis: synovial fluid aspiration Polarized microscopy shows rhomboid-shaped, weakly positive birefringent crystals WBC count typically 2,000-10,000 with >50% polymorphonuclear cells
Treatment: treat like acute gout
Classification of Vasculitides Large Vessel Vasculitis
Takayasu's arteritis: Primarily affects the aorta and its primary branches ACR classification criteria (3 out of 6 criteria): Age of disease onset <= 40 years Claudication of the extremities Decreased pulsation of one or both brachial arteries Difference of > 10 mmHg in systolic BP between arms Bruit over one or both of the subclavian arteries or abdominal aorta Arteriographic narrowing or occlusion of the entire aorta, its primary branches, or large arteries in the proximal upper or lower extremities not due to atherosclerosis, fibromuscular dysplasia, or other causes
Giant Cell (temporal) arteritis: Chronic vasculitis of large and medium size vessels Associated with polymyalgia rheumatica ACR classification criteria (3 out of 5 criteria): Age >= 50 years at time of disease onset Localized headache of new onset Tenderness or decreased pulse of temporal artery ESR > 50 mm/h Biopsy of the temporal artery revealing necrotizing arteritis with predominance of mononuclear cells or a granulomatous process with multinucleated cells Medium-Sized Vessel Vasculitis
Polyarteritis nodosa: Systemic necrotizing vasculitis without granulomas Not associated with p-ANCA (myeloperoxidase) antibody ACR classification criteria (3 out of 10 criteria): Otherwise unexplained weight loss >= 4 kg Livedo reticularis (a purplish network-like pattern of the skin) Testicular pain or tenderness Myalgias (excluding shoulder and hip girdle), weakness, or polyneuropathy Mononeuropathy or polyneuropathy New onset diastolic BP > 90 mmHg Elevated serum BUN (> 40 mg/dL) or Cr (> 1.5 mg/dL) Evidence of hepatitis B infection Characteristic arteriographic abnormalities (aneurysms, vessel occlusion) Biopsy of small or medium-sized artery containing polymorphonuclear cells
Isolated CNS vasculitis: Rare disorder most commonly diagnosed in patients with CNS symptoms/signs with evidence of cerebral vasculitis by angiography and a positive leptomeningeal biopsy Small Vessel Vasculitis
Churg-Strauss arteritis (allergic granulomatosis and angiitis): Classically involves arteries of the skin and lung but can be generalized ACR criteria (presence of >= 4 is 85% sensitive and 99.7% specific): Asthma Eosinophilia > 10% on differential Mononeuropathy or polyneuropathy Migratory or transient pulmonary infiltrated on chest x-ray Paranasal sinus abnormality Biopsy containing perivascular eosinophil accumulation
Wegener's granulomatosis: Systemic vasculitis of medium/small arteries/venules/arterioles Typically produces granulomatous inflammation of upper and lower respiratory tracts and necrotizing pauci-immune glomerulonephritis Associated with c-ANCA (proteinase-3 antibody) ACR criteria (presence of >= 2 is 88% sensitive and 92% specific): Nasal or oral inflammation (ulcers, bloody nasal discharge) Abnormal chest x-ray showing nodules, fixed infiltrates, or cavities Abnormal urinary sediment (microscopic hematuria or RBC casts) Granulomatous inflammation on biopsy of an artery or perivascular area
Microscopic polyarteritis: Primarily affects capillaries, venules, or arterioles. Pulmonary-renal vasculitic syndrome (pulmonary hemorrhage/renal failure) p-ANCA + in 40-80% patients
Hypersensitivity vasculitis (3 vasculitic syndromes): Henoch-Schönlein purpura: Systemic vasculitis characterized by tissue deposition of IgA-containing immune complexes ACR criteria (presence of >= 2 is 87% sensitive and 88% specific): Age <= 20 years at disease onset Bowel angina Palpable purpura Biopsy showing granulocytes in the walls of arterioles and/or venules Hypersensitivity vasculitis (cutaneous leukocytoclastic angiitis): Includes drug-induced vasculitis and serum sickness ACR criteria (presence of >= 3 is 71% sensitive and 84% specific): Age > 16 years Palpable purpura Maculopapular rash Known medication taken prior to disease onset Biopsy showing granulocytes around vessels Essential cryoglobulinemic vasculitis: Immunoglobulins precipitate in the cold and dissolve on rewarming
Type 1: monoclonal immunoglobulin (IgM or IgG)
Type 2: monoclonal IgM with activity against polyclonal IgG (mixed)
Type 3: polyclonal IgM with activity against polyclonal IgG (mixed) Often associated with hepatitis C Small vessel inflammation results from deposition of immunoglobulins and complement in the vessel walls
Antinuclear Antibody Subtypes
Subtypes
Diseases
Comments
Anti-ds-DNA
SLE
Does not occur in classic drug-induced lupus but may occur in lupus induced by anti-TNF agents
Anti-Sm
SLE
Associated with lupus nephritis
Anti-Ro/SSA
SLE Neonatal SLE Sjögren's Myositis
May indicate an overlap of Sjögren's and SLE
Anti-La/SSB
SLE Sjögren's
May indicate an overlap of Sjögren's and SLE
Anti-U1-RNP
Mixed connective tissue disease (MCTD) SLE
Often seen with Raynaud's
Anti-histone
Drug-induced lupus SLE
Especially sensitive for lupus caused by procainamide, hydralazine, chlorpromazine, and quinidine
Anti-centromere
Systemic sclerosis (Scleroderma)
< 5% of diffuse, 60-80% of limited
Anti-topoisomerase (anti-Scl-70)
Systemic sclerosis (Scleroderma)
40% diffuse, 15% of limited
American College of Rheumatology Criteria for Diagnosis of Systemic Lupus Erythematosus
(>= 4 yields a sensitivity and specificity of > 95%)
Criteria
Definition
Malar rash
Fixed erythema, flat or raised, over the malar eminences, tending to spare the nasolabial folds
Discoid rash
Erythematosus raised patches with adherent keratotic scaling and follicular plugging; atrophic scarring may occur in older lesions
Photosensitivity
Skin rash as a result of unusual reaction to sunlight, by patient history or physician observation
Oral Ulcers
Oral or nasopharyngeal ulcerations usually painless, observed by a physician
Arthritis
Nonerosive arthritis involving 2 or more peripheral joints, characterized by tenderness, swelling, or effusion
Serositis
Pleuritis (convincing history of pleuritic pain or a rub heard by a physician or evidence of a pleural effusion) ORpericarditis (documented by EKG, rub, or evidence of a pericardial effusion)
Renal disorder
Proteinuria ( > 0.5 gm/day or >= 3+ on dipstick if quantitation not performed) ORcellular casts (may be red cell, hemoglobin, granular, tubular, or mixed)
Neurologic disorder
SeizuresORpsychosis (in the absence of offending drugs or known metabolic derangements such as uremia, ketoacidosis, or electrolyte imbalances)
Hematologic disorder
Hemolytic anemia (with reticulocytosis) OR leukopenia (< 4,000/mm3 on >= 2 occasions) ORlymphopenia (< 1,500/mm3 on >= 2 occasions) ORthrombocytopenia (< 100,000/mm3 in the absence of offending drugs)
Immunologic disorders
Antiphospholipid antibodyORanti-ds-DNA (antibody to native DNA in abnormal titer) OR Anti-Sm (presence of antibody to Sm nuclear antigen) ORfalse positive serologic test for syphilis known to be positive for >= 6 months and confirmed by a negative Treponema pallidum immobilization or fluorescent treponemal antibody absorption test
Antinuclear antibody
An abnormal titer of antinuclear antibody by immunofluorescence or an equivalent assay at any point in time and in the absence of drugs known to be associated with "drug-induced lupus" syndrome
Drugs that cause lupus: Hydralazine, Isoniazid, Procainamide, Methyldopa, Quinidine, Chlorpranimide.
Scleroderma Renal Crisis Clinical Characteristics Acute onset of renal failure usually in the absence of chronic kidney disease Abrupt onset of moderate to marked hypertension Due to ischemic activation of the renin-angiotensin system Often associated with hypertensive retinopathy
Urine sediment: Usually normal but can have mild proteinuria Microscopic hematuria and granular casts may be seen
Chronic: mucoid intimal thickening®concentric "onion-skin" thickening Management Aggressive blood pressure control is the mainstay of treatment ACE inhibitors (not ARBs) are the agent of choice Achieve gradually (10-15 mmHg) Avoid nephrotoxins
