Diagnostic Approach to Adult Erythroderma: A Rare Case of Sezary Syndrome.

Background & Objective: Sezary Syndrome is an uncommon leukemic variant of Cutaneous T-cell Lymphoma (CTCL), comprising only 5% of all CTCL cases. The rarity of this syndrome emphasizes the critical need to comprehend its distinct clinical presentation, diagnosis, and treatment. Case Presentation: A 51-year-old man was admitted with itchy, persistent, and extensive erythematous patches, ulcers, lumps, lymphadenopathy, alopecia, and nail dystrophy that had been present for eight months. Laboratory findings showed elevated LDH and 𝛽2-microglobulin. Peripheral blood smear analysis confirmed the presence of Sezary cells, while imaging revealed multiple lymph node enlargements. Skin biopsy and immunohistochemistry suggested cutaneous T-cell lymphoma (CTCL), while immunophenotyping verified a diagnosis of Sezary syndrome . The patient underwent fluid therapy, systemic antibiotics, topical antibiotics, phototherapy, and chemotherapy. Tenofovir was given due to the hepatitis B co-infection. Despite the improvement when discharged from the hospital, the patient's health eventually deteriorated, which led to death at home. Conclusion: This patient presented with Sezary Syndrome, exhibiting atypical dermatologic manifestations that must be differentiated from other causes of erythroderma. This case highlights the importance of a comprehensive diagnostic approach, including clinical evaluation, laboratory tests, imaging, and biopsies. Sezary Syndrome is an inherently aggressive malignancy, characterized by a poor response to treatment and a low 5-year survival rate.