Differentiating Skin Ulcers
Chronic skin ulcers are a diagnostic challenge. Anatomical distribution and the appearance of the ulcer base are key to determining the underlying etiology.
Common Etiologies
| Type | Typical Location | Key Characteristics |
|---|---|---|
| Venous | Medial malleolus | Shallow, irregular, often with stasis dermatitis/hemosiderin staining. |
| Arterial | Distal digits/toes | Deep, “punched-out,” painful, minimal granulation tissue. |
| Neuropathic | Pressure points (soles) | Painless, callus-rimmed, associated with diabetes. |
Clinical Pearls
- Pyoderma Gangrenosum: A sterile neutrophilic ulcer with violaceous, undermined borders. Often associated with IBD.
- Malignant Ulcers: Consider SCC (Marjolin’s ulcer) in any long-standing, non-healing wound or burn scar.
High-Yield Exam Pearl:
- Venous vs. Arterial: Leg elevation improves pain in venous ulcers but worsens pain in arterial ulcers due to decreased perfusion.
- Marjolin’s Ulcer: Represents aggressive SCC arising in a chronic wound or scar. Always biopsy if a non-healing ulcer shows proliferative tissue or fails to respond to standard care.