Diffuse Lymphadenopathy Syndrome as a Flare-Up Manifestation in Lupus and Mixed Connective Tissue Disease Following Mild COVID-19

Case series Patients: Male, 28-year-old • Female, 25-year-old • Female, 68-year-old Final Diagnosis: Lupus Symptoms: COVID-19 pneumonia with deteriration of clinical symptoms • lymphadenopathy Medication: — Clinical Procedure: — Specialty: Rheumatology OBJECTIVE: Rare coexistence of disease or pathology BACKGROUND: Manifestations of Coronavirus disease 2019 (COVID-19), caused by the SARS-CoV-2 virus, are highly variable among healthy populations. In connective tissue disease patients, the spectrum of clinical manifestations is even broader. In mild COVID-19 patients, diffuse lymphadenopathy (DL) has not been described as a late manifestation, and only severe COVID-19 has been associated with lupus flare-ups. Herein, we report 3 cases of connective tissue disease patients that presented with DL after diagnosis and complete resolution of mild COVID-19 disease. CASE REPORTS: Case 1. A 28-year-old man with inactive lupus, mixed connective tissue disease (MCTD), and a history of lung and cutaneous involvement. He presented with fever, polyarthralgia, and multiple lymphadenopathies 3 weeks after COVID-19 disease resolution. After evaluation, immunosuppressive treatment was initiated, with rapid response. Case 2. A 25-year-old woman with inactive lupus with a history of articular, hematologic, and cutaneous involvement. Four weeks after resolution of COVID-19 disease, she presented with malaise and cervical lymph-adenopathies. After laboratory testing and imaging, she was treated for lupus flare-up, with rapid response. Case 3. A 68-year-old woman with inactive lupus with a history of articular and cutaneous involvement. Four weeks after COVID-19 resolution, she presented with malaise and cervical and axillary lymphadenopathies. After extensive evaluation, immunosuppressive treatment resulted in a rapid response. CONCLUSIONS: After 3 to 4 weeks of mild, outpatient-treated COVID-19 and complete resolution of symptoms, 3 patients with connective tissue disease presented diffuse lymphadenopathy associated with inflammatory and constitutional symptoms. Infectious and neoplastic causes were thoroughly ruled out. All patients responded to reintroduction of or an increase in immunosuppressive therapy. We recommend considering the diffuse lymphadenopathy as a possible post-acute COVID-19 syndrome (PACS) manifestation in these patients, mainly when they are in the inactive phase.