A coincidence of rheumatoid arthritis, autoimmune thyroid disease and vitiligo in a single patient: a possible pathogenetic linkage.

It has been widely observed that disorders with an autoimmune pathogenesis occur with increased frequency in patients with a history of another autoimmune disease (AD). The numbers of documented cases of a co-occurrence of different autoimmune diseases in a single patient in addition to studies investigating the possible common etiopathogenesis of these diseases have increased in recent years. Available data suggest that the presence of one AD should alert the clinician to the possibility of a second AD. In this report, we aimed to draw attention to these potential coincidences and the possible pathogenetic linkages between three distinct ADs in a single individual diagnosed with rheumatoid arthritis, autoimmune thyroid disease and vitiligo. Further documentation of observations of possible coincidence are required in order to yield results that may shed light on the biological pathways of these diseases.