A review and approach to the diagnosis of blue toe syndrome

Blue toe syndrome (BTS) is characterized by an acute onset of often painful, blue/violaceous discoloration of one or multiple toes due to impaired blood flow, leading to ischemia of the affected digits. There are a plethora of etiologies of BTS that can be broadly classified into several factors: vascular obstruction, autoimmune conditions, hyperviscosity syndromes, infections, drug-induced occurrences, and vasospasm. In this review, we aimed to provide clinicians with an understanding of the etiologies of BTS and provide an approach to a patient presenting with BTS.