Crystal Arthritis - Gout Flashcards
What is Gout?
Crystal arthropathy, associated with blood uric acid levels.
Important Differential Diagnosis of Gout.
Septic Arthritis.
Risk Factors of Gout (7).
- Male.
- Obesity.
- High Purine Diet (e.g. Meat, Seafood).
- Alcohol.
- Diuretics.
- Existing CVD/Kidney Disease.
- Family History.
Clinical Features of Gout.
Single Acute Hot Painful Swollen Joint.
What are Gouty Tophi?
Subcutaneous deposits of uric acid, typically affecting the small joints and connective tissues of the hands, elbows and ears.
Which joints are most affected by gout in the hands?
DIPs.
Which joints are typically affected by gout? (3)
- Base of the Big Toe - Metatarsophalangeal joint (70% of 1st presentations) - “podagra”.
- Wrist.
- Base of the Thumb - Carpometacarpal Joint.
Clinical Presentation of Gout.
Flare - episodes lasting several days and reaching maximal intensity within 12 hours but symptom free between episodes.
Aetiology of Gout (2).
- Urate crystals are deposited in the joint.
2. Chronic Hyperuricaemia - Uric Acid > 0.45 mmol/L.
What can increased production of uric acid? (3)
- Myeloproliferative/Lymphoproliferative Disorder.
- Cytotoxic Drug.
- Severe Psoriasis.
What can decrease excretion of uric acid? (3)
- Drugs - Diuretics.
- Chronic Kidney Disease.
- Lead Toxicity.
What is Lesch-Nyhan Syndrome?
HGPRTase Deficiency - X-linked Recessive in boys : gout, renal failure, neurological deficits.
Diagnosis of Gout (2).
- Clinical Diagnosis + Aspiration of Fluid from Joint.
2. EXCLUDE SEPTIC ARTHRITIS.
What will Aspirated Fluid show in Gout? (4)
- No bacterial growth.
- Needle-Shaped Crystals.
- Negatively Birefringent of Polarised Light.
- Monosodium Urate Crystals.
What will an X-Ray show in Gout? (3)
MELP :
- Maintenance of joint space.
- Joint Effusion (Early Sign).
- Lytic Lesions in Bone.
- Punched out Erosions that have sclerotic borders with overhanging edges.
