Compression of the dorsalis pedis artery: a novel cause of blue toe syndrome.

Blue toe syndrome (BTS) is an important vascular condition characterized by painful blue discoloration of one or more digits. It is frequently due to emboli and is important because of the risk of progressive ischemia and tissue loss. A 53-year-old male presented with recurrent episodes of painful blue discoloration and blistering of the skin of the right hallux. On examination, the patient was found to have a cool, blue-purple great toe; all peripheral pulses were present. The patient was investigated for coagulopathy and potential sources of emboli, but the only abnormality was significant stenosis of the dorsalis pedis artery due to extrinsic compression by the extensor hallucis brevis tendon. In the absence of any other embolic source or abnormality, we believe that this case presents a novel and potentially remediable cause of BTS and indicates the need for a careful search for an underlying lesion when common causes of BTS have been excluded.