What is Livedo Reticularis?
Livedo reticularis is a net-like, violaceous to reddish-blue mottled discoloration of the skin caused by interruption of blood flow in dermal arteries due to vasospasm, inflammation, or vascular obstruction. 1, 2
Clinical Appearance and Pathophysiology
- The pattern appears as a "fishnet" reticular cyanotic discoloration, most commonly affecting the extremities 2, 3
- It results from changes in cutaneous blood flow within the dermal arterioles, creating the characteristic mottled appearance 2, 4
- The discoloration can be transient or persistent, ranging from reddish-blue to purple 4
Classification: Primary vs. Secondary
Primary (Benign) Livedo Reticularis:
- Affects mainly middle-aged females and is a benign disorder 4
- Represents a physiological vasospastic response to cold (cutis marmorata) 5
- Most patients are asymptomatic and require no treatment 3
- Can be congenital or idiopathic 5
Secondary Livedo Reticularis:
- Associated with underlying systemic diseases of varying severity 1
- Common causes include connective tissue diseases, vasculitis, hypercoagulable states, and embolic events 2
- The American College of Cardiology identifies it as a clinical sign of hypoperfusion in cardiogenic shock, manifesting as cold extremities with livedo reticularis 6
Critical Distinction: Livedo Racemosa
- Livedo racemosa is the pathologic variant that requires urgent evaluation 3, 4
- The American Heart Association identifies antiphospholipid antibody syndrome (APS) as a critical diagnosis, where livedo serves as a prognostic marker of severe disease with arterial/venous thrombosis and pregnancy morbidity 7
- Unlike benign livedo reticularis, livedo racemosa typically persists or progresses despite antiplatelet/anticoagulant therapy 3
Key Diagnostic Considerations
Determine the clinical course: 1
- Chronic, stable pattern suggests primary livedo
- Acute onset raises concern for embolic disease, thrombosis, or vasculitis
- Fulminant presentation indicates medical emergency
Assess for associated findings: 1
- Cutaneous nodules, retiform purpura, or necrosis suggest secondary causes
- Painful ulcers indicate more severe vascular compromise 2
- Systemic symptoms (fever, weight loss, arthralgias) point toward autoimmune or inflammatory conditions
Evaluate for life-threatening conditions:
- In cardiogenic shock, livedo reticularis appears with cold extremities, decreased mentation, oliguria, and lactate >2 mmol/L 6
- The American Heart Association recommends evaluating for atheroembolic disease when livedo presents with peripheral signs of cholesterol emboli 7
Common Pitfalls
- Do not dismiss livedo reticularis as purely cosmetic without excluding secondary causes, particularly in patients with systemic symptoms, thrombotic events, or pregnancy complications 7
- The American College of Cardiology emphasizes that livedo racemosa typically does not improve with anticoagulation, so persistence of the pattern should not be interpreted as treatment failure 8
- Younger patients with livedo and thrombotic events require evaluation for inherited hypercoagulable states (Factor V Leiden, prothrombin gene mutation, protein C/S deficiency) 7