Poster 212 Atypical Presentation of Gout Masquerading as Severe Osteoarthritis in a Woman with Longstanding Metatarsalgia: a Case Report

Abstract

Disclosures: J. Luz, No Disclosures: I Have No Relevant Financial Relationships to Disclose. Case Description: Patient with prior 1st TMT arthrodesis and 5 months S/P 4th metatarsal osteotomy reports persistent severe pain, intermittent swelling and redness on the base of 5th metatarsal and generalized metatarsalgia. Orthotics, iontophoresis, and months of narcotic analgesics failed to improve pain. Examination demonstrated no abnormalities. X-ray showed a well-healed osteotomy, intact TMT arthrodesis, and DJD. MRI showed mild edema in subcutaneous tissue of dorsal 5th metatarsal base with no bone marrow edema or fracture. Program Description: 50-year-old obese woman with severe left foot osteoarthritis (OA) and chronic metatarsalgia. Setting: Tertiary center outpatient clinic. Results or Clinical Course: MUS examination at the 5th TMT joint revealed synovial thickening, hyperechoic stippling within thickened joint capsule, and positive color power Doppler signal consistent with the MUS appearance of gouty arthropathy. The 1st MTP joint also showed chronic synovitis and crystal deposition. Uric acid level was 6.1; CRP was elevated at 8.6. She received an ultrasound-guided corticosteroid injection into the inflamed joint followed by gout treatment with allopurinol, Colcrys for flare prophylaxis, and hydroxychloroquine. Pain gradually improved; narcotics, and later Colcrys, were weaned off. One year after initiating treatment, patient remained pain-free. Follow-up MUS examination showed prior erosive joint changes but no active synovitis. Discussion: Gout has been considered a preferential male disease, often presenting as podagra. Women with risk factors (e.g. obesity, HTN) can also develop gout and are more likely to present atypically, particularly in the setting of underlying OA. Ultrasound assists in the diagnosis of gout via detection of tophi, the double contour sign, and synovial pathology. Chronic gouty inflammation can cause bony erosions, as also seen in severe OA. Conclusions: MUS can greatly aid clinicians in the differential diagnosis of arthritis and crystalline disease. Presence of severe OA in the foot should raise clinical suspicion for underlying inflammatory arthritis, including gout.