Ch 3 - Rheumatology: RA Flashcards
What is Rheumatoid arthritis (RA)?
Systemic autoimmune inflammatory disorder of unknown etiology affecting multiple organ systems
What does RA affect in in joints?
Synovial lining of diarthrodial joints
What happens to joints in chronic RA?
Symmetric erosive synovitis develops in the joints and leads to articular destruction
What is pathognomic of RA?
Joint erosions
What is the most important destructive element of RA?
Pannus formation
What is a pannus?
Membrane of granulation tissue that covers the articular cartilage at joint margins
What do fibroblast-like cells do during pannus formation?
Invade and destroy the periarticular bone and cartilage at joint margins
What is vascular granulation tissue composed of?
Proliferating fibroblasts
Numerous small BV’s
CD4 T-lymphocytes
Collagen fibers w/in phagolysosomes
What are the genetic factors of RA?
– MHC on chr 6
– Class II MHC allele HLA-DR4
What is the epidemiology of RA?
Female to male 2:1
20-60 yo, peak 40-50
What are the classification categories for RA?
- Morning joint stiffness
- Arthritis of >3 joints
- Arthritis of the hand joints
- Symmetric arthritis
- Rheumatoid nodules
- Rheumatoid Factor (RF) +
- Radiographic changes
Describe morning stiffness in RA.
Must last at least 1 hour before maximal improvement
What are the 14 possible joints involved in RA?
Bilateral PIP joints, MCP joints, wrist, elbow, knee, ankle, and MTP joints
What are Rheumatoid nodules?
Subcutaneous nodules over extensor surfaces, bony prominences, or in juxta-articular regions
Describe radiographic changes of RA.
Erosions, bony decalcification, and symmetric joint-space narrowing seen on hand and wrist X-ray
Describe the MC onset pattern of RA.
Insidious (50-70%) Slow onset over weeks to months Diffuse MSK pain Morning stiffness Low grade fever Joint swelling, erythema
Describe synovial fluid in RA.
- Low viscosity
- WBC = 1,000–75,000/mm3
- > 70% PMNs
- Transparent—cloudy
What % of patients with RA are RF +?
85%
Other 15% fulfill other criteria for dx
What are diseases that can have RF +?
SLE Scleroderma Sjögren’s Viral Parasitic Bacterial Neoplasms Hyperglobulinemic
What is the sensitivity and specificity of cyclic citrullinated peptide Abs for RA?
80% sensitivity and 90-95% specificity for RA
What other diseases can cyclic citrullinated peptide Abs be seen in?
Psoriatic arthritis
TB
Autoimmune hepatitis
What are early radiographic findings in RA?
– Soft tissue swelling
– Joint space
What are late radiographic findings in RA?
– Uniform joint space narrowing due to loss of articular cartilage (hips, knees, etc.)
– Axial migration of the hip (protrusio acetabuli)
– Malalignment and fusion of joints
What is seen near attachment of the joint capsule in RA?
Marginal bone erosions
What is bone washout in RA?
(+) Juxta-articular osteopenia
What does cervical spine involvement in RA lead to?
Cervical atlantoaxial (A-A) subluxation (>2.5 to 3 mm)
What is a Boutonniere deformity?
Rupture of central slip of extensor hood of PIP joint causes lateral band subluxation causing PIP flexion, MCP and DIP hyperextension
What causes swan neck deformity in RA?
- Flexor tenosynovitis l/t MCP flexion contracture
- Contracture of the intrinsic l/t PIP hyperextension
- Contracture of deep finger flexor muscles and tendons l/t DIP flexion
What causes ulnar deviation of fingers in RA?
Weakening of ECU, UCL, RCL l/t wrist radial deviation which inc torque on ulnar finger flexors causing flexor/extensor mismatch and ulnar deviation of fingers when patient tries to extend fingers
Which tendons are involved in de Quervain’s Tenosynovitis?
EPB and APL
What can early RA be confused with at the wrist?
de Quervain’s Tenosynovitis
What is the Piano-key sign?
Floating ulnar head dorsally in the wrist
What causes ulnar head floating?
Synovitis at the ulnar styloid l/t rupture or destruction of the UCL l/t laxity of the radioulnar joint
What is resorptive arthropathy?
Bone resorption l/t shortened digits and phalanges appear retracted w/ skin folds
What is the pseudobenediction sign?
Stretched radioulnar ligaments allow the ulna to drift upward l/t rupture of 4th and 5th extensor tendons and inability to extend
What is the most common direction for Atlantoaxial (A-A) joint subluxation?
Anterior
What are causes of Atlantoaxial (A-A) joint subluxation in RA?
- Tenosynovitis of the transverse ligament of C1 l/t rupture
- Odontoid or atlas erosion
- Basilar invagination
What is an abnormal A-A space with cervical flexion?
> 2.5 to 3 mm is considered abnormal
What is recommended pre-operatively in RA patients?
C-spine flexion-extension x-rays are recommended to ensure there is no cervical instability
What is Protrusio acetabuli?
Inward bulging of the acetabulum into the pelvic cavity
What are common ankle deformities in RA?
- Ligament weakness leading to hindfoot pronation
* Tarsal tunnel syndrome
What are common foot deformities in RA?
- Hammer toe deformities
- Claw toe deformities
- Hallux valgus deformity
Which patients are more likely to have extra-articular manifestions of RA?
– RF (+)
– Rheumatoid nodules
– Severe articular disease
– MHC class HLA DRB1 alleles
What are subcutaneous rheumatoid nodules?
Form subcutaneously in bursae and along tendon sheaths over pressure points and extensor forearm
What can enhance development of subcutaneous rheumatoid nodules?
Methotrexate
What disorders are subcutaneous nodules seen in?
RA
Gout
What are vasculitic lesions seen in RA?
Leukocytoclastic vasculitis
Palpable purpura
What are ocular manifestions of RA?
- Keratoconjunctivitis sicca (dry eye syndrome)
- Episcleritis
- Scleritis
What are pulmonary manifestions of RA?
- Interstitial lung disease
- Pulmonary fibrosis
- Pleurisy
- Inflammation of the cricoarytenoid joint
- Bronchiolitis obliterans
What is Caplan’s syndrome?
- Intrapulmonary nodules histologically similar to rheumatoid nodules
- RF (+)
- Assoc w/ RA and pneumoconiosis in coal workers
- Granulomatous response to silica dust
What are the classic findings of pericarditis?
Chest pain
Pericardial friction rub
EKG: diffuse ST elevations
What is Xerostomia?
Dryness of the mouth secondary to decreased salivary secretion
What type of anemia is seen in RA?
Hypochromic-microcytic anemia
What is Felty’s Syndrome?
Classic triad of RA, splenomegaly, leukopenia
Which patient’s get Felty’s syndrome?
- Seropositive RA w/ nodules
- 5th or 7th decades w/ RA > 10 years
- 2/3 Women
- Assoc w/ leg ulcers
What type of rehab is done in acute RA?
Severely inflamed joints, actual splinting is used to produce immobilization with twice-daily full and slow passive range of motion to prevent soft-tissue contracture
What type of exercise should be used with mild RA?
Mild disease (moderate synovitis) requires isometric program
What are the benefits of isometric exercise?
– Least periarticular bone destruction and joint inflammation/pain
– Restores and maintains strength
– Max muscle tension with min work, fatigue, and stress
What types of exercise should be avoided in RA?
Isotonic and isokinetic exercise may exacerbate the flare and should be avoided
Why should superficial moist heat not be used in acutely inflamed joints?
Increases collagenase enzyme activity that causes increased joint destruction
What are indications for orthotics in RA?
- Dec pain and inflammation
- Red wt through joint
- Joint stabilization
- Joint rest
What is the therapeutic range for ASA?
ASA is 15 to 25 mg/dL
Toxic > 30 mg/dL
What are types of Nonbiological disease-modifying antirheumatic drug (DMARD)?
Hydroxychloroquine Sulfasalazine Methotrexate Leflunomide Cyclosporine Gold intramuscular, oral Azathioprine
What are side effects of Hydroxychloroquine?
Retinopathy
Hyperpigmentation
What are side effects of Sulfasalazine?
Myelosuppression
GI disturbances
What are side effects of Methotrexate?
Stomatitis Myelosuppression Hepatic fibrosis Cirrhosis Pulmonary involvement Worsens rheumatoid nodules Teratogenicity
What are side effects of Leflunomide?
Hepatotoxicity
N/D
HTN
Teratogenicity
What are side effects of Cyclosporine?
Renal dysfunction Tremor Hirsutism HTN Gum dysplasia
What are side effects of Gold intramuscular, oral?
Myelosuppression
Proteinuria
Diarrhea (#1, oral)
Rash (#1, intramuscular)
What are side effects of Azathioprine?
Myelosuppression
Hepatotoxicity
Lymphoproliferative disorders
Where is a synovectomy MC in RA?
Extensor tenosynovitis at wrist
Where are athrodesis MC in RA?
Ankle
What are poor prognostic factors of RA?
- Rheumatoid nodules
- RF (+)
- X-ray consistent with erosive disease
- Persistent synovitis
- Insidious onset
- CCP antibodies