Löfgren syndrome, characteristics of Japanese cases: A case and a review of the literature.

Löfgren syndrome (LS) is a sarcoidosis subtype characterised by an acute disease course, bilateral hilar lymphadenopathy (BHL), erythema nodosum (EN), and ankle arthritis. LS in Caucasians appears to be self-limiting; however, our patients require glucocorticoid (GC) treatment. Here, we present a case of LS and review the literature to identify the characteristics of Japanese patients with LS. A 66-year-old woman was referred to Kobe City Medical Center General Hospital; she initially presented with an acute onset of low-grade fever and ankle arthritis, followed by EN. Skin biopsy revealed a noncaseating granuloma, and a chest computed tomography scan displayed BHL; she was diagnosed with LS. Her arthralgia ameliorated spontaneously, but the erythema persisted, necessitating GC treatment. A literature review revealed that the Japanese LS patients showed more fever, were more frequently treated with GCs, and more patients seemed to relapse, which may be explained by the absence of human leucocyte antigen-DR isotype 3, a good prognostic allele in Caucasians. Japanese LS may cause severe symptoms after development because of the differences in human leucocyte antigens from foreign countries. For early diagnosis, it is important to evaluate EN and BHL in patients with polyarthritis involving ankle arthralgia.