Platelet occlusion1,4,6,10 | | In addition to a skin biopsy, the following lab findings may be helpful |
Heparin necrosis (from heparin or low molecular weight heparin), heparin-induced thrombocytopenia (HIT), type II10 | Often on the abdomen > extremities. Lesions may be distant sites or sites of heparin infusion or injection. Onset 4-10 days after treatment or <24 hours if drug used within 100 days. Postop highest risk. New venous or arterial thrombus (venous > arterial) (Type I is with platelets >100,000 μL and benign course) | Platelets <100,000 μL or >50% drop from original with a + HIT antibody |
Thrombocytosis, from myeloproliferative disorder6 | See Table 25-2 | |
Paroxysmal nocturnal hemoglobinuria (PNH) | Complement-mediated hemolytic anemia, hypercoagulability state, smooth muscle dystonia, cytopenia, aplastic anemia, MDS, evolution to AML, Budd–Chiari syndrome | CBC with differential and flow cytometry, showing ↓CD55 and CD59 Urine hemosiderosis |
TTP | See Table 25-1 | |
Cold-related gelling or agglutination (eg, cryoglobulinemia, cold agglutinins)1 | See Table 25-4. In addition, cryoglobulinemia type I (monoclonal) is associated with multiple myeloma and Waldenstrom's. Cold agglutinins in adults are associated with lymphoproliferative disease and in children infections (eg, Mycoplasma pneumonia, mononucleosis, and HIV) | |
Occlusion secondary to organism invading vessel1 | Invasive fungus, pseudomonas, strongyloidiasis, or leprosy in immunosuppressed patients or with history of travel to endemic areas | In addition to skin biopsy sent for routine histology, an additional biopsy may be sent for culture Culture blood and other affected body fluids |
Occlusion from systemic coaggulopathies1,11–13 |
Inherited hypercoagulable states | Venous or arterial thrombi, miscarriages in women | ↑ PT/INR, PTT Protein C and S, antithrombin III, prothrombin 20210A, factor V Leiden mutation |
Warfarin necrosis1 | Onset 1-10 days after exposure Large irregular bullae with eventual necrosis on breasts, buttocks, thighs, and penile skin. More common in obese women or those with underlying hypercoagulopathy (eg, protein C or S or ATIII deficiency), may be postinfectious. Can have purpura fulminans | Nonspecific |
Purpura fulminans1 | Branching palpable purpura leading to peripheral symmetrical gangrene. Can have sepsis with DIC (refer to Table 25-1) or be postinfectious | ↑ PT/INR, PTT, D-dimer, fibrin degradation products ↓ Fibrinogen, platelets Bacteria cultures may be positive. P.smear shows schistocytes |
Antiphospholipid antibody or lupus anticoagulant1,13 | Acute and painful purpura, livedo reticularis and racemosa, and anetoderma. Usually age <40 years. Arterial thrombus, recurrent venous thrombi, or spontaneous abortions Associated with SLE (40%-50% of SLE pts r-w), malignancy, infection, or drugs | + Anticardiolipin or B2-glycoprotein antibodies + Lupus anticoagulant (↑PTT) |
Occlusion from emboli1 |
Cholesterol | M > F. Acral distribution Arterial or cardiac catheter, prolonged anticoagulation, acute thrombolytic therapy, artherosclerosis, hypertension, and tobacco use are risk factors Can be multisystemic | In addition to characteristic skin biopsy findings, CBC with differential, showing eosinophilia Other lab abnormalities will depend on affected organ |
Oxalate crystal | Acral distribution | Other than characteristic skin biopsy findings, may have hyperoxaluria |
Endocarditis | Associated with IV drug use and prosthetic valves Stigmata include Osler's nodes, Janeway lesions, and splinter hemorrhages | Blood cultures, EKG Transthoracic and/or transesophageal echocardiogram |
Occlusion from reticulocytes |
Sickle cell disease | Can have symptoms of anemia from chronic hemolysis, infections with encapsulated organism from infracting spleen, osteomyelitis from infracting bone, and pain crisis | CBC shows anemia Sickle-shaped RBCs or Howell-Jolly bodies on peripheral smear Hb electrophoresis |
Calciphylaxis14 | F > M. Painful lesions leading to well-demarcated nonhealing ulcers. Can localize to extremities. Proximal distribution (eg, on trunk, buttock, and thighs) has poorer prognosis. Associated with chronic renal failure, diabetes, obesity, and poor nutrition | In addition to skin biopsy, the following lab findings are suggestive: hyperphosphatemia, elevated calcium-phosphate product (>70 mg/dL). Can also have ↑PTH, Ca, BUN, alkaline phosphatase |