Rheum Flashcards
List DDX for arthritis
MONOARTICULAR
- Septic arthritis
- GOUT
- psedogout
- OA
- Trauma
POLYARTICULAR SYMMETRICLA
- rheumatoid flare
- psoratic arthrtiis
- polymylagia rheumatica
- ank spont
POLYARTICULAR ASSYMETRICAL
- gonoccal arthritis
- ARF
- Reactive arthritis
- viral arthritides
Discuss indications and contraindications for joint aspiration
INDICATIONS
- Obtain joint fluid for anaylsis
- drain tense haemarthroses in patients with trauma and haemophilia
- to evaluate whether a laceration communicates with the joint space.
Contraindications - relative
- cellulitis overlying the injection site
- coaguloapthy
Describe technique for knee tap
- Aseptic
- Local anaethetics
- Flex knee to 15-20 degrees
- palpate the anteromedial patellar edge at the patellar midpoint or superior portion
- Insert 18g needle 1cm medial to this point direted toward the posterior surface of the patella
Discuss different synovial fluid finding by arthritis type
NON INFLAMMATORY
- colour : yellow
- Viscosity ; thick and stringy
- Synovial WBC: 200-2000
- PMN- variable
- Gram stain -ve
INFLAMMATORY
- Colour : yellow/white
- Viscosity: variable
- WBC 2000-50000/mm3
- PMN- variable
- Gram stain -ve
SEPTIC
- Colour : Cloudy/opaque
- Viscosity: thin/watery
- WBC >25000/mm3 +LR 2.9, >50000 +LA 7.7, >100000 LA28
- PMN- >90%
- Gram stain +ve in 30-65% of cases
Describe septic arthritis
Bacterial infection of diarthrotic joint space
Can occur simultaneously with other forms of inflammatory arthritis - fever is common with inflammatory flares and infection can cause precipitation of crystals
Risk factors
- Age over 80
- Low socioeconoic status
- IVDU
- alcoholism
- diabetes
- skin infection
- advanced HIV or other immunocompromised sate
- chronic arthritis (particularly RA, crystalline and degenerative)
- recent injection
List Microbiology of septic joint by age groups and demographic groups
NEONATES
- Staph aureas
- GBS
- GNR bacteria
CHILDREN
- HIB
- Staph aurea
Adolescents and Young adults
- N. Gonorrhoea
- chlaymydia
- stah
Older adult
- S aureas
- strep
- GNR bacteria
SICKLE CELL
-Salmonella
IVDA
- Pseudomonas,
- S. aureas
- GNR bacteria
Discuss management of septic arthritis
ORTHO review
Fluclox 2g Q6 hourly
if MRSA suspected use Vancomycin 30mg/kg
If IVDU consider psuedomonas coverage with cipro or ceftazadime
Discuss gonococcal arthritis
Represents a clinical and pathologic course distinctly different from that of other bacterial infections.
Systemic gonococcal infection complicates 0.5%-3% of mucosal infection and is manifested with two somewhat overlapping MSK syndromes
1) localised septic arthritis - more commonly oligo than mono predominatnly in the knees and wrist.
2) true disseminated gonococcal is manigested with bacteremia, and a triad of tenosynovitis, dermatitis and migratory polyarthralgia +- puruelent arthritis
- skin lesions are usually painfless visculopustular
Risk factors for DGI
- Recent mensturation –
- pregnancy or the immediate postpartum state
- congenitial or acquired complement deficienes
- SLE
WBC in synovial fluid tend to be lower than than in nongonococcal arthritis.
Treat with IV ceftriaxone 24 hourly + 1gram of oral azithromycin
Describe GOUT and its risk factors
Acute intermittent gout typically is manifested in middle aged men or postmenopausal women often in the setting of excess alcohol, or dietary indiscretion, acute physioloigcal stress or new medications.
Risk factors
- Chronic obesity
- htn
- diabetes
- thiazide diuretics
- cyclosporine
- purine rich diets ( meat, seafood (ancovies and shellfish), beer and legumes)
Acute precipitation of uric acid crystals from supersaturated extracellular fluid. Uric acid is a normal metabolic endpoint of purine metabolism
Discuss clinical features of gout
Most common joint is the great toe MTP, the knee the ankle and the trasal joints.
Pain is often exquisite at onset. Systemic features include fever can be present. Without treatment the attack is self limited peaking during the 24-48 hour mark and lasting about a week
Subsequent attacks tend to be closer together involve more joints and last longer.
Discuss management of GOUT
ACUTE
1) Nsaids - indomethasin is typically given 50mg TDS, Ibuprofen 800mg DS - if initiated promptly relief occurs in the first 24 hours
2) -Colchicine -inhibits microtuble formation and impedes the inflammatory response to the presence of cyrstals
- 1mg followed by 500mic one hour later
- contraindicated in haematological, renal or hepatic insufficiency
3) Steroids
- prednisone 15-30mg dialy until symptoms abate
Chronic
-Allopurinol 50mg daily for 4 weeks than increase by 50mg every 2-4 weeks max dose of 900mg dialy
Describe pseudogout (calcium pyrophosphate, dihydrate deposition)
Results when calcium complex cyrstals form across articular surfaces. CPPD is manifest on radiographs as chondrocalcinosis
When precipitating crystals trigger an inflammatory synovitis termed pseudogout.
Risk factors
- aging
- joint surgery
- haemochromatosis
- hypothyroidism
- hyperparathyroidsm
- amyloidosis
- hypomagnesemia
- Wilsons diseaes
Clinical feature and mangement are similar to gout
Discuss Rheumatoid arthritis
Women 2-3x more commonly then men with a peak incidence in the 4th and 5th decade of life.
Common presentation is that of a prodromal period of fatigue, weakness and MSK pain with or wihtout fever and weight loss that may have been present for weeks to months.
Acute presentation may have only warm, tender and swollen joints that may be difficult to distinguish from a viral arthropathy
Long standing changes of RA include MCP and PIP joint swellling, ulnar deviation, swan neck and boutoneire deformities of the hand and limitation of dorsiflexion of the wrist.
Discuss extra-articular features of RA
Occur in up to half of patient with RA and include
- subcut nodules
- vasculitis of the skin
- pulmonary fibrosis
- mononeuritis multiplex
- pericarditis
- Sjogrens and Felty’s syndrome.
Discuss IX of RA
Focused on ruling out other cause of arthritis in the ED. But diffinitive diagnosis can be challenging and involves confirmatory serology.
Synovial fluid analysis is helpful to rule out infectious or cyrstalline processes. Arthrocentesis reveals inflammaotry fluid with WBC between 4000-50000 with more PMN than would be expected for crystaline inflammation up to 75%
