Elephantiasic Pretibial Myxedema with Graves' Disease: Spontaneously Induced and Dramatically Resolved after Radioiodine Treatment

Abstract

Pretibial myxedema (PTM) is an uncommon autoimmune manifestation of Graves's disease. It is commonly associated with ophthalmopathy and typically localized in the pretibial region [1]. It is speculated that thyroidstimulating hormone receptor antibody (TRAb) plays an important role in the pathological mechanism. TRAb can trigger an autoimmune response, leading to the inflammatory and infiltrative process with the production of large amounts of hyaluronic acid and glycosaminoglycans in the dermis and subcutaneous tissue [2]. High TRAb values and antigen release from thyroid cells may induce PTM [3]. Elephantiasic PTM is rare (5%) [4]. The management of elephantiasic PTM remains a challenge because of the poor patient response and high rate of recurrence.