Morphea with Seronegative Inflammatory Arthritis and Normal Acute Phase Reactants: A Case Report

Localised scleroderma, also known as morphea, is an immune-mediated fibrosing disorder that primarily affects the skin and subcutaneous tissues. While traditionally considered purely a cutaneous disease, extracutaneous manifestations (especially inflammatory arthritis) are increasingly being appreciated. The combined presence of morphea and inflammatory arthritis is rare and can be difficult to diagnose, particularly when inflammatory markers and serological testing are non-contributory. Case Summary : We describe a 41-year-old woman with long-standing biopsy-proven morphea who over 2 years developed chronic, asymmetric inflammatory arthritis of the left wrist and hand small joints. On examination, she had active synovitis with restricted movements of her wrist, classical hyperpigmented plaques on her face with dermal sclerosis and feature of linear sclerotic band over her forehead. Laboratory findings including erythrocyte sedimentation rate, C-reactive protein, rheumatoid factor, anti-cyclic citrullinated peptide antibodies, and antinuclear antibodies, were within normal limits. Magnetic resonance imaging of the left wrist demonstrated joint space narrowing, cartilage thinning, erosions, subchondral cysts, bone marrow edema, and synovial thickening, confirming inflammatory arthritis. The patient showed significant clinical improvement following treatment with tapering corticosteroids, methotrexate, and structured physiotherapy. Conclusion : This case highlights that inflammatory arthritis may occur in morphea despite normal inflammatory markers and negative serology, emphasizing the importance of early recognition and multidisciplinary management to prevent irreversible joint damage.