DP13 Relapsing polychondritis presenting with necrotic vasculitic skin ulcers mimicking pyoderma gangrenosum in an 80-year-old patient with rheumatoid arthritis

Abstract

Relapsing polychondritis is a rare immune-mediated connective­-tissue disorder primarily affecting cartilaginous structures. Cutaneous manifestations occur in 35% of cases but are rarely inaugural, often mimicking neutrophilic dermatoses or systemic vasculitides, leading to diagnostic delay. The aim of this study was to describe an atypical presentation of relapsing polychondritis revealed by necrotic vasculitic skin ulcers clinically indistinguishable from pyoderma gangrenosum, emphasizing the importance of systematic clinicopathological correlation. We report an 80-year-old patient presenting with chronic painful leg ulcers. Comprehensive clinical examination, skin biopsy with direct immunofluorescence, laboratory investigations and systematic multisystem assessment were performed. Histopathological findings were correlated with clinical features to establish diagnosis according to the McAdam, Damiani–Levine and Michet criteria. An 80-year-old man with long-standing seropositive rheumatoid arthritis presented with bilateral painful deep leg ulcers (8 × 6 cm and 7 × 5 cm) evolving over 3 months, with undermined violaceous borders and necrotic bases clinically indistinguishable from pyoderma gangrenosum. Associated findings included viola­ceous papules on the elbows, knees and hands, and purpuric toe lesions. Histopathology revealed leucocytoclastic vasculitis. Direct immunofluorescence was negative. Systematic evaluation identified previously unrecognized bilateral auricular chondritis with floppy eroded pinnae sparing lobules, nasal alar ecchymoses, sudden-onset bilateral sensorineural hearing loss confirmed by audiometry, conjunctivitis, and recurrent bipolar aphthosis. Laboratory investigations showed elevated inflammatory markers (C-reactive protein 64 mg L−1, erythrocyte sedimentation rate 78 mm h−1) without cryoglobulinemia, antineutrophil cytoplasmic antibodies or myelodysplasia. Diagnosis fulfilled the McAdam, Damiani–Levine and Michet criteria. High-dose corticosteroid therapy (methylprednisolone 1 mg kg−1 per day) with methotrexate 15 mg weekly achieved complete ulcer healing within 8 weeks. Relapsing polychondritis may exceptionally present with necrotic vasculitic ulcers mimicking pyoderma gangrenosum, particularly with associated autoimmune disease. Recognition of suggestive cutaneous lesions combined with systematic assessment for cartilaginous, auditory and ocular involvement is essential for early diagnosis, avoiding misdiagnosis and enabling prompt effective treatment.