Connective Tissue And Joint Diseases Flashcards
What is SLE?
- Systemic lupus erythematosus is an autoimmune disorder leading to inflammation and tissue damage in multiple organ system.
- It involves autoantibody production, deposition of immune complexes, complement activation, and accompanying tissue destruction/vasculitis.
- Associated with HLA-DR2 and HLA-DR3.
What are the clinical features associated with neonatal lupus?
- Skin lesions
- Cardiac abnormalities such as AV block and transposition of the great vessels
- Valvular and septal defects
What are the 11 diagnostic criteria of SLE?
MD SOAP BRAIN
- Malar rash (butterfly rash)
- Discoid rash
- Serositis
- Oral or nasal ulcers
- Arthritis
- Photosenisitivity
- Blood
- Renal
- ANA antibody positive
- Immune antibodies (Anti-ds DNA, Anti-Smith, Antiphospholipid, Antihistone, Ro (SS-A) and La (SS-B))
- Neurological
What is the diagnostic criteria for SLE?
Patient musta have at least 4 criteria (at least 1 clinical criteria and 1 immunologic criteria) OR biopsy proven lupus nephritis with a positive ANA or anti-dsDNA.
How is SLE managed?
- Avoid sun exposure
- NSAIDs for less severe symptoms
- Corticosteroids for acute flares
- Hydroxychloroquine for long term therapy, but baseline and annual eye examination as it causes retinal toxicity
- Cyclophosphamide for active glomerulonephritis
Which conditions are ANA positive?
- SLE
- RA
- Scleroderma
- Sjogren syndrome
- Mixed connective tissue disease
- Polymyositis and dermatomyositis
- Drug-induced lupus (antihistone Abs is more sensitive and specific, kidneys and CNS are not affected)
What are the most common causes of death in SLE?
Opportunistic infections and renal failure. So, renal function should be monitored and treated.
What is scleroderma?
- AKA systemic sclerosis, it is a chronic connective tissue disorder that can lead to widespread fibrosis involving multiple organs.
- Cytokines stimulate fibroblasts, causing an abnormal amount of collagen deposition so, it is the high quantity of collagen that causes the problems associated with this disease.
- It has 2 types: limited and diffuse
What are the facial features of scleroderma?
- Microstomia
- Lip retraction
- Beaked nose
- Perioral furrows
How is scleroderma diagnosed?
- ANA positive in almost all patients
- Anticentromere antibody is very specific for limited form
- Antitopoiomerase I antibody is very specific for diffuse form
What is Sjögren syndrome?
- A multi organ autoimmune disease characterized by lymphocytes infiltrate and destroy the lacrimal and salivary gland.
- Associated with HLA-DR3
What are the clinical features of Sjögren syndrome?
- Dry eyes
- Dry mouth and tooth decay
- Arthralgias, arthritis, fatigue
- interstitial nephritis and vasculitis
How is Sjögren syndrome diagnosed?
- ANA
- Ro (SS-A) and La (SS-B)
- Schirmer test: normal is >15 mm in 5 minutes
- Salivary gland biopsy most accurate but not needed for diagnosis
What is Rheumatoid Arthritis?
- A chronic inflammatory autoimmune disease involving synovium of joints and inflammation of synovium can cause damage to cartilage and bone.
- Associated with HLA-DR4
What are the characteristic features of joint involvement?
- Symmetrical, loss of mobility of >3 joints
- Can involve every joint except DIP joints, commonly involves PIP, MCP and wrists
- Morning stiffness lasting >1 hour
- Ulnar deviation of MCP joint
- Boutonnière deformities of PIP (flexed PIP, hyperextended DIP)
- Swan-neck contractures of the fingers (flexed MCP, hyperextended PIP, flexed DIP)
- C1-C2 subluxation and instability, so cervical spine radiographs should be taken prior to surgery to avoid complication during intubation
How is RA diagnosed?
- Presence of inflammatory arthritis of multiple joints
- Symptoms lasting at least 6 weeks
- Elevated ESR and CRP
- Positive serum RF or ACPA
What are the radiological findings of RA?
Currently not required for diagnosis:
1. Loss of juxta-articular bone mass near the finger joints
2. Narrowing of the joint space
3. Bony erosions at the margin of the joint
How is RA managed?
- Exercise helps maintain range of motion and muscle strength
- Symptomatic treatment (NSAIDs or low dose corticosteroids)
- Methotrexate (DMARDs)
What is gout?
It is an inflammatory monoarticular arthritis caused by the crystallization of monosodium urate in joint. Hyperuricemia is a hallmark of the disease, but it itself doesn’t indicate gout.
What are the 4 stages of gout?
- Asymptomatic hyperuricemia: no treatment required
- Acute gouty arthritis: initial attack of sudden onset of exquisite pain that wakes the patient up from sleep with cellulitis changes. Commonly involves the first metatarsophalangeal joint (podagra).
- Intercritical gout: asymptomatic period
- Chronic tophaceous gout: characterized by tophi formation that occur due to poorly uncontrolled gout
How is gout diagnosed?
Joint aspiration and synovial fluid analysis is the ONLY way to make a definitive diagnoses and to rule out septic arthritis. It shows needle-shaped and negatively birefringent urate crystals.
How is gout managed?
- Avoid secondary causes or triggers of hyperuricemia
- During acute attack:
- Bed rest
- NSAIDs or colchicine or corticosteroids
- Prophylactic therapy:
- Indicated if patient has had at least 2 acute gouty attacks or presence of tophi
- NSAID or colchicine for 3-6 months to prevent acute attack
- Uricosuric drugs (probenecid) indicated if 24-hour urine uric acid is <800 mg/day, but contraindicated in decreased renal function
- Xanthine oxidase inhibitors (allopurinol) indicated if 24-hour urine uric acid is >800 mg/day
What is pseudogout?
Calcium pyrophosphate crystals deposit in joints, leading to inflammation. Common in elderly with degenerative joint disease. Presents similar to gout, but commonly occurs in larger joints such as knee.
How is pseudogout diagnosed?
- Joint aspirate is required to definitive diagnosis showing weakly positively birefringent rod-shaped and rhomboidal crystals in synovial fluid.
- Radiographs show chondrocalcinosis which is cartilage calcification
