Chilblains With Tumid Lupus Features in a Patient With Sjögren's Syndrome: A Case Report

Sjögren's syndrome is an autoimmune disorder characterized by lymphocytic infiltration of exocrine glands, primarily affecting the lacrimal and salivary glands, resulting in dry eyes and mouth. We report a case of a 22-year-old female with Sjögren's syndrome (diagnosed at age 14), who developed chilblain-like lesions with histopathological features of tumid lupus. The patient presented with low-grade fever and painful erythematous papules on the fingers, toes, ears, face, and trunk. Serological workup revealed multiple autoantibodies (anti-SSA (Sjögren's-syndrome-related antigen A), anti-SSB (Sjögren's-syndrome-related antigen B), anti-centromere, anti-U1RNP (anti-U1 ribonucleoprotein), ANA (antinuclear antibody), and rheumatoid factor). Skin biopsy demonstrated interface dermatitis with lymphoplasmacytic infiltration and increased dermal mucin. After an inadequate response to conventional therapy (hydroxychloroquine, methotrexate, prednisone, and topical treatments), the patient showed significant improvement with belimumab. This case highlights the overlap between Sjögren's syndrome and lupus spectrum disorders. It demonstrates the potential efficacy of B-cell-targeted therapy in managing refractory cutaneous manifestations of autoimmune overlap syndromes.