In station 5 you may be asked to assess a patient with an acute hot swollen tender joint with restriction of movement
History (3 minutes):
- Timing questions: since when, sudden/gradual onset (hours/days/weeks/months), progression, previous episodes (if so, how often, which joint(s), 1 or both sides, big or small joints, how long for, when does flare/attack happen etc.)
- Which joint? Joint pain + severity, swelling, stiffness, redness, range of movement and function
- Is it native/prosthetic joint
- Any trauma
- Septic arthritis:
- Fever/rigors, feeling unwell, able to mobilise/put weight through the joint, recent infection, any injections/bites, any iv drug use, any surgery/arthroscopy, cut/boil/rash/ulcer/nearby infection, any immunosuppression eg. HIV, diabetes
- Gout:
- Alcohol (beer, port, stout), fizzy/energy drinks
- Red meat/sweetbreads/liver/kidney/shellfish/sardines/anchovies
- Kidney problems eg. kidney stones
- Diuretics and aspirin and CVS risk factors: hypertension, high cholesterol
- Tophi
- Dehydration/fasting
- Surgery/exercise/medical stress eg. infection
- Blood disorders, fever/night sweats/lymph nodes, thyroid problem, psoriasis
- Pseudogout:
- Any thyroid/parathyroid/haemochromatosis/wilsons disease
- Reactive Arthritis:
- Recent diarrhoea and vomiting, recent STI/new sexual partner/dysuria/discharge, red eye, travel history, skin rashes, mouth/genital ulcers, back pain, dactylitis (swollen finger or toe)
- Haemarthrosis:
- Warfarin/bleeding disorder
- Avascular necrosis:
- Steroid use
- Psoriatic arthritis:
- Personal/family history of psoriasis, nails, red eye, plantar fasciitis, Achilles tendonitis, dactylitis, back pain
- IBD arthritis:
- Bloody diarrhoea, weight loss, personal/family history of IBD
- RA:
- Systemic upset: fever, night sweats, weight loss, fatigue, lymph nodes
- Raynauds
- Skin, nails, hair: rashes, photosensitivity, hair loss, ulcers
- Eyes: dry/red/painful/change in vision
- CVS/Resp/GI/Neuro systems review
- PMH: joint problems/psoriasis/IBD/autoimmune conditions
- Fx: as above
- Dx: treatments tried, immunosuppression
- Sx and impact
Examine (3 minutes):
- Observations particularly temperature (can have fever with septic arthritis but also crystal arthritis)
- Examine the joint- look, feel (temperature, tenderness, swelling), move (active, passive). Examine other joints.
- Gait
- Extraarticular features:
- Eyes (iritis)
- Mouth (ulcers)
- Skin (psoriasis, keratoderma blenorrhagica etc)
- Tophi eg. on ears/elbows/hands
- Systemic examination: CVS, Resp, Abdo
ICE+Explanation (2 minutes)
VIVA
Investigations:
FBC (infection, haematological cause of gout), U+E (renal disease), LFT (alcohol, pre-antibiotics), CRP (raised in septic arthritis and crystal arthritis), ESR, clotting (pre-aspirate), Ca, Mg, ferritin, TFT (pseudogout, 15% with gout have hypothyroidism), urate (can be normal/raised/low in acute gout attack so not very useful), glucose/Hba1c, lipid profile (gout, CVS risk factors)
Xray joint (if suspected osteomyelitis, AVN, fracture)
Aspirate joint pre antibiotics ideally (gram stain, WCC, culture, polarised light microscopy for crystals) Contraindications: prosthetic joint, cellulitis, overlying psoriasis, increased INR, low platelets.
Blood cultures (septic arthritis)
Urine dipstick and culture
Stool culture
ECG (CVS risk assessment)
STI screen- urine for gonorrhoea and chlamydia if male (+rectal and pharyngeal swabs if homosexual male), vulvovaginal swab for gonorrhoea and chlamydia if female, HIV and syphilis serology and hepatitis screen, stool culture for shigella if homosexual male
MRI if osteomyelitis is suspected
Consider RF, Anti-CCP, ANA, HLA-B27 if more than 1 joint involved/indicated depending on history.
Differential Diagnoses:
- Septic Arthritis
- Crystal Arthritis (gout, pseudogout)
- Reactive Arthritis
- Trauma
- Haemarthrosis
- Monoarticular presentation of RA, psoriatic arthritis, IBD-arthritis
- Bursitis, cellulitis, osteomyelitis
- Avascular necrosis
Management:
Treat as septic arthritis if clinical suspicion (eg. purulent/cloudy aspirate, fever) with iv antibiotics following local guidelines then tailor according to culture results (liaise with microbiology team) NB: can still be septic arthritis even if patient does not have a fever and even if gram stain/culture are negative
Liaise with orthopaedic team especially if it is a prosthetic joint (?surgical drainage)
Analgesia
Non-weight bearing
Monitor signs and symptoms and CRP
Septic Arthritis
Acute swelling, warmth, pain and redness of a single joint
Often knee, hip. Also ankle, shoulder, wrist, elbow
Risk factors: reduced host defence, direct penetration, joint damage
Cause: remote infection spread in blood, adjacent osteomyelitis, soft tissue infection near the joint, iatrogenic (eg. arthroscopy), trauma.
Organisms: staph aureus, group A/B strep, gram negative bacilli. Can also be due to gonococcal/meningococcal infection.
Aspirate is positive in 70-90%. Often 50000-100000 cells/mm3 and >85% polymorphs, low glucose.
Blood culture positive in 50%.
NB: gout can coexist!
Xray- early changes include periarticular osteopenia, joint effusion, soft tissue swelling. Late changes (2-3 weeks) include periosteal reaction, reduced joint space, erosions, subchondral bone destruction
Disseminated gonococcal infection (1% of septic arthritis): young adults, 1-3% of patients with gonorrhoea, migratory polyarthralgia/tenosynovitis, can be monoarthritis/polyarthritis. Some patients with gonococcal infection have a rash
Gout
A crystal deposition disease
Disorder of purine metabolism resulting in hyperuricaemia either from overproduction or undersecretion of uric acid resulting in deposition of urate crystals in the joints/bursae.
Urate= a purine breakdown product
Typically acute monoarthritis of the first MTP joint. Also ankles, knees and upper limb joints. Predilection for cooler/acral sites where the solubility of crystals is reduced due to cool temperature. Can be polyarticular too.
Males >females.
Only ~15% with increased urate get gout
Can become chronic. Presence of tophi indicates severe, recurrent, chronic gout. Tophi are large aggregations of urate crystals. Can get uric acid renal stones and nephropathy.
Causes:
- Alcohol excess
- Drugs: thiazides and loop diuretics, aspirin
- Acidosis (lactate/diabetic ketoacidosis/respiratory)
- CKD
- Myelo/lymphproliferative disorders
- Psoriasis
- Tumour lysis secondary to chemo
- Excess dietary purine intake
- Lesch Nyhan syndrome
Xray- early :soft tissue swelling, late: punched out mouse bite erosions and overhanging edges and calcification. No periarticular osteopenia. Joint space preserved until late.
Management:
- Lifestyle changes: reduce dietary intake of purine, red meat, liver and kidney, reduce alcohol, lose weight, exercise, stop smoking, stay hydrated
- Rest and ice during acute phase
- Manage CVS risk factors; diabetes, cholesterol, hypertension
- NSAIDs+PPI (diclofenac/indomethacin for 1-2 weeks) if no contraindications (renal disease, severe heart failure, peptic ulcer disease)
- Colchicine (side effects: diarrhoea, bone marrow) Careful: elderly, renal, hepatitis, drug interactions
- Steroids intraarticular/short course oral/intramuscular if septic arthritis excluded and failed/can’t tolerate NSAIDs or colchicine
- Stop diuretic if on for hypertension and find an alternative (don’t stop if on diuretic for heart failure)
- Check urate at 4-6 weeks.
- Allopurinol for prophylaxis (xanthine oxidase inhibitor). Delays resolution of acute attack and triggers it. Continue it if already on it otherwise start in 2 weeks after inflammation has settled. Offer if 2 attacks in 1 year/tophi/erosions/renal insufficiency/renal stones/diuretics/pre-chemo. Cover with NSAID+PPI/Colchicine/prednisolone when starting. Monitor U+E and titrate according to urate. Aim urate <300 micromol/L. Side effects: gi upset, rash, hepatotoxic, renal. Alternatives include febuxostat, benzbromarone, probenecid, pegloticase.
Reactive Arthritis
Reiter’s triad: conjunctivitis, urethritis, dysentery
Acute onset sterile inflammatory synovitis within 4 weeks of urogenital/enteric infection (assymetrical, oligoarthritis, affecting lower limb joints usually).
Mean interval is 14 days between genital symptoms and arthritis.
Lasts > 1month usually
HLA-B27 positive in 60%
Salmonella, Shigella, Yersinia, Chlamydia, gonorrhoea, campylobacter, ureaplasma
Infection not identified in 40%
Often young adults, M>F
MSK features: arthritis, enthesitis, dactylitis, spondylitis/sacroilitis.
Extraarticular features: low grade fever, conjunctivitis/anterior uveitis, ileitis/colitis, urethritis/prostatitis/haemorrhagic cystitis, circinate balanitis/vulvitis, keratoderma blennorhagica, hyperkeratotic nails, psoriasiform rash, oral ulcers, rarely aortic regurgitation/left ventricular dilatation/pericarditis
Management: bed rest, splints, ice packs/warm compresses, treat STI and contact tracing, NSAIDs, intraarticular steroid, oral steroid trial. DMARDs such as sulphasalasine, methotrexate.
Most recover within 1 year (usually 2-6 months). 20% become chronic. Complications are more likely if HLA-B27 positive.
Written by Dr Sarah Kennedy
Resources used to write this document include those listed in the references section of this webpage and also:
Rheumatology Secrets by Sterling West