{Reference Type}: Case Reports {Title}: Löfgren Syndrome: Clinical Presentation, Clinical Course, and Literature Review. {Author}: Flores R;Caridade S; {Journal}: Cureus {Volume}: 15 {Issue}: 1 {Year}: Jan 2023 暂无{DOI}: 10.7759/cureus.33651 {Abstract}: Löfgren syndrome is an acute presentation of sarcoidosis that comprises fever, bilateral and symmetric hilar lymphadenopathies, polyarthritis, and erythema. We present the case of a 34-year-old male patient who presented with ankle monoarthritis without a history of a traumatic event. Contralateral ankle arthritis associated with erythema nodosum and fever developed one week later. Laboratory tests showed anemia, thrombocytosis, and elevated inflammatory parameters. A chest CT revealed symmetrical mediastinal and hilar adenopathies. A transbronchial biopsy was compatible with granulomatous lymphadenitis, and the diagnosis of Löfgren syndrome was confirmed. Our case report and literature review emphasize the wide web of mimicry of acute sarcoidosis. Secondary forms of acute sarcoidosis are likely to benefit from additional and more complex immunomodulatory therapies. Close monitoring and follow-up should be conducted because it is possible that these patients experience higher rates of recurrence or relapse.