Synopsis
Recognise blue-toe ischaemia, distinguish thromboembolic occlusion from cholesterol crystal showering and direct urgent source-focused multidisciplinary care.
- Blue-toe syndrome describes painful blue or violaceous digits from small-vessel occlusion; palpable pedal pulses do not exclude it because proximal large arteries may remain patent.
- Thromboembolic blue toe is often abrupt and source-related, whereas cholesterol crystal embolisation may evolve subacutely with livedo, kidney injury and inflammatory laboratory features.
- Ask about recent angiography, vascular surgery and anticoagulant or thrombolytic exposure, while remembering that cholesterol embolisation can also occur spontaneously.
Key red flags
Rapidly spreading digital cyanosis, rest pain, sensory or motor loss, or fixed tissue change indicates threatened tissue and needs immediate vascular review.
Blue toes with livedo reticularis, rising creatinine, eosinophilia or systemic symptoms after angiography suggests cholesterol crystal embolisation affecting multiple organs.
Fever, murmur, positive blood cultures or retinal and neurological emboli raises infective endocarditis and requires urgent sepsis and cardiac assessment.
Sudden blue or violaceous toe with pain, coolness or tenderness indicates digital ischaemia and warrants urgent vascular assessment.
Palpable dorsalis pedis or posterior tibial pulses are compatible with distal microembolisation and must not be used to dismiss blue-toe syndrome.
Blue toes or livedo with subacute renal decline, constitutional symptoms and eosinophilia after arterial instrumentation suggests multisystem cholesterol embolisation.
Abrupt focal ischaemia after loss of a graft, aneurysm thrombosis or cardiac embolic event favours platelet-fibrin or thrombus material.
Fever, new murmur, splinter haemorrhages or positive cultures with digital lesions requires urgent assessment for infective endocarditis.
Investigation priorities
Define tissue viability and distinguish distal embolisation from whole-limb acute ischaemia.
Management branches
A patient develops a painful purple toe with palpable pedal pulses two weeks after coronary angiography and creatinine is rising.
- Inputs: document timing, procedure route, skin distribution, whole-limb viability, pulses and Doppler, renal trajectory, urine, eosinophils, inflammatory markers and medicines.
- Reasoning: preserved pulses localise disease distally, while delayed renal decline plus cutaneous emboli after arterial instrumentation makes cholesterol crystal showering more likely than one large thrombus.