Purpura / necrosis / retiform rash
When Does Purpura, Necrosis, or Retiform Rash Need Derm Discussion?
A concise clinician guide for non-blanching, necrotic, painful, retiform, or ulcerative rashes.
Quick answer
Purpuric / Necrotic Rash Triage
- Derm discussion is reasonable when purpura is systemic, painful, necrotic, retiform, ulcerative, rapidly progressive, or biopsy site selection may change diagnosis.
- ICU, ID, surgery, Rheum, nephrology, or heme may be first or concurrent depending on systemic features.
- Fresh lesion timing can matter when vasculitis biopsy is being considered. *
Derm discussion is reasonable when
Higher-Yield Consult Context
- Palpable purpura with renal, GI, pulmonary, neurologic, hematologic, or systemic symptoms.
- Retiform purpura, necrosis, painful livedo, ulcers, or rapidly progressive violaceous lesions.
- Biopsy may distinguish vasculitis, vasculopathy, embolic disease, calciphylaxis, infection, or autoimmune disease.
Workup or other service first when
Better First Step
- Sepsis, purpura fulminans, or shock requires stabilization and appropriate emergency services first.
- Necrotizing infection or source control concern requires surgery/ED pathway first or concurrently.
- Organ involvement suggests Rheum, nephrology, heme, ID, or ICU may be needed concurrently.
Common pitfall
Keep the Question Specific
Purpura is not one diagnosis. The useful consult asks whether morphology and biopsy can change the service pathway.
FAQ
Clinician Questions
What should I describe?
Whether lesions blanch, are palpable, retiform, necrotic, painful, ulcerative, rapidly progressive, or associated with organ symptoms.
Why does lesion timing matter?
For suspected vasculitis, biopsy yield can depend on choosing a fresh appropriate lesion and sending the right specimen. *
When is surgery first?
Concern for necrotizing infection, deep tissue involvement, source control, or rapidly progressive severe pain should trigger surgical/emergency pathways.
References
Educational tool only. SIC provides clinician-facing educational consult-triage references. SIC does not diagnose, treat, prevent, cure, or mitigate disease and is not a substitute for clinical judgment, local guidelines, institutional referral pathways, or recommendations from your dermatology department. See disclaimer.