MKSAP Quiz: severe knee pain and swelling

MKSAP Answer and Critique

The correct answer is D) Intra-articular methylprednisolone. This item is available to MKSAP 15 subscribers as item 5 in the Rheumatology section.

This patient has gout, which manifests as acute, intermittent attacks of severe pain, redness, and swelling of a joint accompanied by intracellular urate crystals seen on polarized light microscopy of the synovial fluid. The most appropriate treatment for this patient is an intra-articular corticosteroid injection. Early attacks of gout are typically monoarticular and usually involve a joint in the lower extremities, particularly the first metatarsophalangeal joint. Affected joints may be exquisitely tender to the touch and have a painful range of motion. Gout also is associated with an inflammatory synovial fluid leukocyte count during an acute attack and an elevated serum uric acid level, although many patients with hyperuricemia do not develop gout.

Intra-articular corticosteroid injection has been shown to rapidly treat acute gout. This therapy is particularly useful in patients in whom NSAIDs or oral or parenteral corticosteroids are contraindicated. Furthermore, local injection therapy with a corticosteroid only minimally affects glycemic control. However, infectious arthritis must be excluded before this treatment is administered.

Allopurinol would help to decrease this patient's uric acid level. However, use of uric acid–lowering agents during an acute attack does not ameliorate the attack of gout and may prolong an attack or cause a more frequent attack rate. Furthermore, allopurinol may cause a rare but serious hypersensitivity syndrome in patients who have renal insufficiency. Therefore, this agent should be used with caution starting at a low dose in this population group.

Effective treatment of acute attacks of gout involves high-dose therapy with NSAIDs, corticosteroids, or colchicine. Immediately initiating NSAID treatment at anti-inflammatory doses is most likely more important than the specific agent used. However, NSAIDs are contraindicated in this patient because of his chronic kidney disease.

Colchicine is most effective for the treatment of acute gout when used within the first 24 hours of symptom onset but would be less efficacious in this patient, whose symptoms began 4 days ago. This agent is associated with potential bone marrow toxicity, particularly in patients with renal insufficiency.

Corticosteroids may be given orally, intramuscularly, or by intra-articular injection. These agents have similar efficacy to NSAIDs, but a high-dose oral or parenteral corticosteroid may exacerbate this patient's diabetes mellitus and is therefore relatively contraindicated.