Diagnostic Steps and Treatment for Sepsis-Induced Purpura Fulminans
Sepsis-induced purpura fulminans should be diagnosed using a two-step approach that first screens for sepsis-induced coagulopathy (SIC), followed by assessment for overt disseminated intravascular coagulation (DIC), with prompt anticoagulant therapy initiation to prevent devastating microvascular thrombosis and tissue necrosis. 1
Diagnostic Approach
Initial Screening
- Screen septic patients with thrombocytopenia (platelet count <150 × 10^9/L) using SIC diagnostic criteria 1
- Assess for clinical features of purpura fulminans: rapidly progressive purpuric lesions, tissue necrosis, small vessel thrombosis, and DIC 2, 3
- Obtain at least 2 sets of blood cultures (both aerobic and anaerobic bottles) before starting antimicrobials 1, 4
- Perform prompt imaging studies to identify potential infection sources requiring source control 1, 4
Laboratory Assessment
- Complete SIC diagnostic criteria evaluation, including:
- Platelet count
- Prothrombin time-international normalized ratio (PT-INR)
- Sequential Organ Failure Assessment (SOFA) score 1
- If SIC criteria are met, proceed to overt DIC diagnostic criteria assessment:
- Platelet count
- PT ratio
- Fibrin/fibrinogen degradation products (FDP) or D-dimer
- Fibrinogen levels 1
- Monitor for acute hepatic dysfunction ("shock liver"), which may predispose to symmetrical peripheral gangrene (SPG) due to impaired synthesis of natural anticoagulants 1
Treatment Protocol
Immediate Management
- Administer effective intravenous antimicrobials within the first hour of recognition of septic shock or severe sepsis 1, 4
- Use broad-spectrum antimicrobials that cover all likely pathogens, including anaerobes when appropriate 1, 4
- Implement source control measures within 12 hours of diagnosis when feasible 4
Anticoagulant Therapy
- Consider anticoagulant therapy when purpura fulminans is present, despite bleeding being a common finding in DIC 3
- Treatment options based on availability and regional practices include:
Hemodynamic Support
- Target mean arterial pressure ≥65 mmHg in patients requiring vasopressors 1, 4
- Maintain central venous pressure 8-12 mmHg 1
- Ensure adequate urine output ≥0.5 mL/kg/h 1
- Target central venous oxygen saturation ≥70% 1
- Consider guiding resuscitation to normalize lactate in patients with elevated levels 1, 4
Ongoing Management
- Reassess antimicrobial regimen daily for potential de-escalation 1, 4
- Monitor clinical response daily through vital signs, laboratory parameters, and symptom resolution 4
- Continue anticoagulant therapy until resolution of coagulopathy and clinical improvement 2, 5
- Typical duration of antimicrobial therapy is 7-10 days, but longer courses may be necessary for patients with slow clinical response 1, 4
Special Considerations
Symmetrical Peripheral Gangrene (SPG)
- Monitor for SPG, characterized by acral (distal extremity) limb loss due to microvascular thrombosis 1
- Consider timely administration of heparin and antithrombin to reduce risk of microthrombosis in at-risk patients 1
- Be aware that rsTM might not be effective if protein C levels are severely reduced due to hepatic dysfunction 1
Pitfalls to Avoid
- Delaying antimicrobial therapy beyond one hour from recognition of sepsis 1, 4
- Failing to obtain appropriate cultures before starting antimicrobials 1, 4
- Neglecting source control when indicated 4
- Continuing broad-spectrum therapy unnecessarily after pathogen identification 4
- Underestimating the need for anticoagulation in purpura fulminans despite bleeding risk 2, 3
- Failing to recognize the pathophysiologic distinction of purpura fulminans as a highly thrombotic subtype of DIC requiring specific management 2
The management of sepsis-induced purpura fulminans requires a multidisciplinary approach with early recognition, aggressive antimicrobial therapy, appropriate anticoagulation, and meticulous supportive care to improve outcomes in this devastating condition 2, 6, 7.