A case of Buerger's disease with vasculopathy and skin fibrosis requiring differential diagnosis from systemic sclerosis.

Buerger's disease is characterized by peripheral ischemia due to occlusion of small- and medium-sized arteries in the extremities. This report describes a case of Buerger's disease in a 51-year-old male who presented with findings resembling systemic sclerosis. The patient exhibited Raynaud's phenomenon in year X-3, which developed to skin hardening, nail avulsion, and ulceration of the right fingers in year X. Diagnostic testing showed positive microvasculopathy on nailfold videocapillaroscopy (NVC) and positive fibrosis on skin biopsy. Although the patient fulfilled the 2013 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) classification criteria for systemic sclerosis, several findings in this case were atypical for systemic sclerosis, including left-right asymmetry in finger involvement, nail loss, and negative autoantibody tests. Contrast-enhanced computed tomography showed poor perfusion of the right ulnar artery, and a heavy smoking history was established in the patient case. Therefore, based on Shionoya's criteria, he was diagnosed with a case of Buerger's disease confined to the upper extremity. Smoking cessation and vasodilator therapy resulted in the prompt resolution of ischemic symptoms, skin hardening, and ulcerations. Furthermore, NVC abnormalities improved, and ulnar artery occlusion showed reperfusion on repeat testing. The present case suggests that hypoxemia-driven microvasculopathy may contribute to vascular occlusion and skin fibrosis observed in this atypical presentation.