Lofgren syndrome in close temporal association with mild COVID-19 - Case report.

Coronavirus infection disease 2019 (COVID-19) has been linked to the development of various autoimmune disorders. Lofgren syndrome, consisting of bilateral pulmonary hilar lymphadenopathy, erythema nodosum and polyarthritis, is a rare autoimmune disease that represents an acute form of sarcoidosis. We present the case of Lofgren syndrome developing in close temporal association with COVID-19. Clinical presentation consisted of fever, bilateral lung lymphadenopathy, arthralgias and erythema nodosum. Hilar lymph node biopsy revealed pathology consistent with sarcoidosis. Three weeks prior to presentation, the patient experienced respiratory symptoms. Serological examination at the time of presentation revealed positive IgM and IgG antibodies against SARS-CoV-2 nucleocapsid protein. Most symptoms resolved following a course of oral prednisone. This case report suggests a possible link between COVID-19 and the development of sarcoidosis, however, further studies are needed to conclude this association.