Synopsis
Distinguish reversible livedo reticularis from pathological livedo racemosa and retiform infarction, assess perfusion and thrombotic drivers, select deep tissue appropriately, and escalate ischaemia without empirical anticoagulation.
- Physiological livedo reticularis is a regular closed purple network provoked by cold, usually symmetrical on limbs and substantially resolving with warming.
- Livedo racemosa is persistent, irregular, broken and often wider-meshed across limbs, buttocks or trunk; it raises antiphospholipid syndrome, Sneddon syndrome and other systemic vasculopathies.
- Retiform purpura is fixed non-blanching angular or branching ischaemia that progresses towards ulcer or necrosis and indicates occluded or destroyed vessels rather than benign vasospasm.
Key red flags
Rest pain, tissue coldness, absent pulses, fixed retiform purpura, necrosis, new focal neurology, severe headache, renal injury, fever, shock, thrombocytopenia, pregnancy morbidity with thrombosis or a rapidly ulcerating livedoid pattern requires urgent specialist review.
Fixed angulated non-blanching patches become painful, blistered or black as branching vascular territories lose flow.
Investigation priorities
Separate functional vasospasm from fixed ischaemia and identify limb-threatening disease immediately.
Management branches
A net-like purple, grey or brown skin pattern is newly noticed.
- Photograph the distribution with consent before and after safe warming and determine whether the network is regular and closed or broken, fixed and widespread.
- Ask about pain, ulcer, thrombosis, pregnancy morbidity, vascular procedures, kidney disease, fever and neurological symptoms and examine pulses, refill, temperature and sensation.