Blue Toe Syndrome in Behçet's Disease: A Case Report

Abstract

BACKGROUND Vascular Behçet's disease (VBD) is a rare but potentially life-threatening subtype of Behçet's disease that is characterized by multisystemic vasculitis. It primarily affects males with ancestry traced back to regions along the ancient Silk Road. Both arteries and veins, regardless of size, may exhibit complications, including aneurysmal degeneration or occlusion. While venous involvement is observed in two-thirds of VBD cases, arterial complications are notably the most severe and lethal. Arterial aneurysmal degeneration is more common than occlusive complications, with larger arteries being predominantly affected in VBD. Data regarding isolated small-vessel arterial occlusive disease in VBD are limited. Given the rarity of this presentation in this patient population, it becomes mandatory to thoroughly evaluate such patients to differentiate small-vessel vasculitis from other similar diseases, such as Raynaud's phenomenon, which has a different etiology and management and generally has a more benign course. Here, we delineate the concept of isolated small-vessel vasculitis as a cause of blue toe syndrome in patients with VBD. CASE REPORT This report describes a distinctive case of vascular Behçet's disease in a 51-year-old man who initially exhibited unilateral blue toe syndrome, which swiftly progressed to dry gangrene of the toes. Despite reports of large-vessel involvement, there is a paucity of data on isolated small-vessel vasculitis-induced digital ischemia in VBD. CONCLUSIONS This atypical case underscores the necessity of clinical discernment in differentiating inflammatory microvascular occlusive disease from vasospastic Raynaud's syndrome, both of which can complicate Behçet's disease.

Figure 1.

Dry gangrene of the left toes up to the metatarsal heads.

Figure 2.

Computed tomography angiogram of the distal left lower limb: Figure A shows patent enhancing left anterior tibial artery above the ankle (yellow arrow) with total occlusion distally at the ankle level (red arrow); Figure B shows calcified total occlusion segment of left dorsalis pedis artery (yellow arrow); Figure C shows re-opacified left dorsalis pedis artery distally with tapering of contrast enhancement; Figure D shows distended left dorsalis pedis artery distally with wall thickening. Features in Figures C and D are highly suggestive of vasculitis.

Figure 3.

Catheter-directed arteriogram of the left lower limb demonstrated a diseased dorsalis pedis artery with areas of total occlusion (red arrow), weak plantar arch perfusion (red circle), patent anterior tibial artery (white arrow), patent posterior tibial artery (yellow arrow) and patent plantar arteries (green arrows).