Rare head and neck myositis with reversible myelodysplastic syndrome: The first reported lupus manifestation as an initial symptom.

Introduction: Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by a dysregulated immune response against self-antigen, leading to multi-organ involvement. Myositis, as an initial manifestation of SLE, is a rare clinical entity, particularly in newly diagnosed patients.

Case presentation: A 27-year-old male presented with massive head and neck swelling, initially suspected to be superior vena cava syndrome (SVCS). Other symptoms included non-scarring alopecia, prolonged fever, oral ulcers, a history of hyperpigmented skin lesions, and progressive lower extremity weakness with edema. Hematological findings revealed persistent pancytopenia (anemia, leukopenia, and thrombocytopenia). Laboratory investigations demonstrated elevated muscle injury markers, including aspartate aminotransferase predominance and elevated creatine kinase. Immunological analysis showed a negative antinuclear antibody by indirect immunofluorescence, high anti-dsDNA titers, and normal complement levels. Bone marrow biopsy revealed trilineage dysplasia with macrophage activation, suggesting underlying hematologic involvement. Contrast-enhanced head and neck computed tomography ruled out SVCS, showing only diffuse muscle and subcutaneous edema. Based on the constellation of clinical, hematological, and imaging findings, the patient was diagnosed with myositis-associated SLE. The therapeutic approach included total plasma exchange (TPE), high-dose corticosteroid pulse therapy, and immunosuppressive induction therapy. Within 1 month of hospitalization, the patient demonstrated significant clinical and laboratory improvement and was subsequently transitioned to maintenance therapy with hydroxychloroquine (200 mg once daily), methylprednisolone (8 mg daily in a tapering regimen), and mycophenolate mofetil (500 mg twice daily). The patient achieved a lupus low disease activity state at follow-up.

Discussion: This case represents a unique presentation of head and neck myositis in a newly diagnosed SLE patient, a manifestation not previously described in the literature. While orbital myositis in SLE has been reported, extensive myositis involving the head and neck as an initial SLE manifestation remains undocumented. Combining TPE, high-dose corticosteroids, and immunosuppressants was critical in disease control. Early recognition and aggressive immunomodulatory therapy are essential in managing such rare and severe SLE presentations.

Conclusion: This case highlights an uncommon initial manifestation of SLE, emphasizing the importance of early clinical suspicion, comprehensive immunological and hematological evaluation, and prompt intervention. A multimodal therapeutic approach, including steroid pulse therapy, induction immunosuppression, and TPE, can lead to favorable clinical outcomes in severe and atypical SLE presentations.