Multicentric reticulohistiocytosis associated with rheumatoid arthritis.

Due to the fact that both multicentric reticulohistiocytosis (MRH) and rheumatoid arthritis (RA) are destructive arthritic and skin disorders, it is often difficult to differentiate one from the other. Here, we report the case of a 67-year-old Japanese woman who had been diagnosed as suffering from RA 20 years ago, and who developed MRH. MRH may be misdiagnosed as RA, but evaluation of the time course of specific symptoms can greatly help in the correct diagnosis.