Löfgren's syndrome is an acute variant of sarcoidosis, characterized by the classic triad of erythema nodosum, bilateral hilar lymphadenopathy, and arthralgia or arthritis. Its low incidence in the Chinese population contributes to limited clinical awareness and diagnostic challenges. We report the case of a Chinese man with long-standing ankylosing spondylitis who had been experiencing recurrent joint swelling, pain, and fever over the past year. At the most recent presentation, he had developed tender, erythematous subcutaneous nodules on the limbs, clinically consistent with erythema nodosum, and was diagnosed with ankylosing spondylitis and Löfgren's syndrome. A comprehensive review of his treatment course revealed a favorable response to glucocorticoid therapy. Notably, he had received adalimumab for ankylosing spondylitis over the past year, and the temporal relationship suggested that adalimumab precipitated Löfgren's syndrome relapse. We further reviewed the literature comparing Löfgren's syndrome between Western and Asian populations. Our findings indicate that Asian Löfgren's syndrome patients are more likely to receive a delayed diagnosis and often require lengthier glucocorticoid therapy. These differences may stem from genetic predispositions influencing disease expression and immune response. Therefore, we recommend that glucocorticoid regimens for Löfgren's syndrome in Chinese patients be carefully titrated and monitored. In a similar manner, when Löfgren's syndrome coexists with other rheumatic immune diseases, tumor necrosis factor-α inhibitors such as adalimumab should be used with heightened vigilance to minimize disease relapse.
Chen et al. (Mon,) studied this question.