How can doctors distinguish smoking-associated Buerger’s disease from systemic sclerosis when both cause fingertip ulcers?

Details

This single-patient clinical case report describes a 48-year-old man referred to hospital after 5 months of Raynaud’s phenomenon and 4 months of ulcers on the first and second digits of his right hand. He had no family history and had smoked 15 cigarettes daily for 28 years. Examination showed severe ulcers, with black necrosis beneath the right first fingernail and yellow necrosis at the tip of the second digit. At the initial visit, neither hand showed skin sclerosis or finger swelling.

Nailfold capillaroscopy showed enlarged loops, hemorrhages, and markedly disorganized capillary architecture: a scleroderma-like pattern. However, avascular areas typical of systemic sclerosis (SSc) were absent. Antinuclear antibody (ANA) testing was positive at 1:160, with homogeneous and nucleolar patterns. SSc-specific autoantibodies listed in the report—anticentromere, anti-Scl-70, anti-U1-RNP, and anti-RNA polymerase III—were negative. Immunoprecipitation showed no specific bands. Despite the absence of disease-specific antibodies, Raynaud’s phenomenon, capillaroscopy findings, and ANA positivity initially suggested SSc.

Systemic evaluation found no interstitial lung disease on chest computed tomography, no pulmonary hypertension on echocardiography, and preserved pulmonary function. His score on the 2013 ACR/EULAR criteria for SSc was 7: Raynaud’s phenomenon contributed 3 points, capillaroscopy 2, and ulcers 2. This was below the 9-point threshold.

His long smoking history prompted suspicion of Buerger’s disease and angiographic evaluation. Angiography showed right ulnar artery occlusion with collateral circulation, without calcification or atherosclerotic changes. The deep palmar arch was visible but tapered distally, and the digital arteries of the first through third fingers did not opacify. He met four of five Shionoya criteria: onset before age 50, heavy smoking, upper limb arterial occlusion, and no atherosclerotic risk factors apart from smoking. No occlusion below the popliteal arteries was observed, but the clinical and angiographic findings supported Buerger’s disease. He met all Olin criteria except age (<45), consistent with probable thromboangiitis obliterans, although coexisting very early SSc could not be fully excluded.

He was advised to stop smoking and received beraprost at 120 μg/day, without improvement. After bosentan at 125 mg/day was introduced, ulcer size decreased markedly and complete healing occurred within 4 months. Photographs on day 126 showed epithelialized fingertip ulcers. At 6 months, nailfold capillaroscopy showed disappearance of enlarged loops and fewer hemorrhages.

The report describes Buerger’s disease as a nonatherosclerotic vasculitis of small- and medium-sized arteries in men in their 30s–40s. It usually affects the lower limbs, but more than 25% of cases involve the upper limb and approximately 5% have isolated upper limb involvement. The ulnar artery is the most frequently affected artery in upper limb cases, matching this patient’s findings. Characteristic angiographic findings are distal lesions, segmental occlusions with corkscrew or tapering appearances, prominent collaterals, and absence of atherosclerosis. The authors state that this patient’s angiographic findings met all these criteria. A prior study of upper extremity angiography in SSc reported predominantly tapering occlusions without abrupt arterial cutoffs, unlike the abrupt or segmental occlusions often seen in Buerger’s disease.

Although Buerger’s disease and SSc are distinct conditions, this case illustrates diagnostic overlap. Raynaud’s phenomenon and the scleroderma-like capillaroscopic pattern initially pointed toward SSc. The lack of avascular areas, negative SSc-specific autoantibodies, and absence of systemic involvement argued against definite SSc, but very early overlap could not be fully excluded and requires long-term follow-up. Scleroderma-like capillaroscopic patterns are rare but have been reported in Buerger’s disease. One earlier report described two patients who improved after smoking cessation and prostanoid therapy. This patient’s capillaroscopic improvement at 6 months was consistent with prior reports of reversibility in Buerger’s disease.

Endothelial dysfunction is thought to contribute to Buerger’s disease, and elevated endothelin-1 levels have been suggested. Smoking cessation remains the cornerstone of treatment, while drug strategies targeting endothelial dysfunction are receiving increasing attention. Bosentan, an endothelin receptor antagonist effective in SSc, has shown promise in Buerger’s disease, including preliminary reports of benefit in refractory cases. The authors conclude that Buerger’s disease should be considered when evaluating digital ulcers with overlapping features such as Raynaud’s phenomenon and a scleroderma-like capillaroscopic pattern. Long-term follow-up is warranted because very early SSc could not be fully excluded. This case also suggests that endothelin receptor antagonists may be a treatment option for selected patients with treatment-resistant Buerger’s disease.

The authors obtained all appropriate patient consent forms, including consent to publish images and clinical information. The patient understood that his name and initials would not be published and efforts would be made to conceal his identity, but anonymity could not be guaranteed. Data sharing was not applicable because no datasets were generated or analyzed. There was no financial support or sponsorship, and no conflicts of interest were declared.