Thank you Serge and John for presenting a very interesting case of a middle-aged male with a history of ESRD on PD, questionable history of APS, with several necrotic skin lesions on his distal fingers, toes, and penis. Ultimately, he was thought to have calciphylaxis, though the biopsy was inconclusive and the distribution of his lesions is quite atypical.
Differential Diagnosis for Necrotic Skin Lesions This list is not all-encompassing, but is a place to start. Various diseases can also cause ischemia via more than one mechanism, so can appear under multiple pathologic mechanisms.
Vasculitis – LOTS of possibilities
- Small Vessel
- Medium Vessel
- Large Vessel
- Calciphylaxis AKA calcemic uremic arteriopathy
- Buerger disease
- Raynauds Phenomenon (primary or secondary)
- Medication side effect: vasopressors
Thromboembolic or Occlussive Disease
- Embolic disease: endocarditis, cholesterol emboli syndrome, atrial myxoma
- Spontaneous thrombosis (hypercoagulability): Antiphospholipid syndrome, HIT, IBD, chronic DIC, PNH, hyperhomocysteinemia
- Frost bite
- Pyoderma Gangrenosum
- Thoracic outlet syndrome
Recall that the diagnosis for Antiphospholipid Syndrome requires both clinical and persistent serologic findings.
- Clinical findings – venous or arterial thrombosis, spontaneous abortion
- Persistent serologic findings – positive at least 12 weeks apart
- Anticardiolipin Ab
- Anti-beta2 glycoprotein Ab
- Lupus anticoagulant assay