Dermatopathology of Rheumatologic Diseases
Cryoglobulins are immunoglobulins that precipitate in small vessels at low temperatures and dissolve at high temperatures. Type 1, monoclonal cryoglobulinemia, is associated with lymphoproliferative diseases. Type 2 and 3 (mixed) cryoglobulinemia is associated with hepatitis C infection. Anywhere from 2 to 15% of patients with cryoglobulin develop cryoglobulinemic vasculitis. Trejo et al. found that the most frequent cutaneous feature seen in cryoglobulinemic vasculitis is palpable purpura, and less commonly seen is Raynaud phenomenon, a skin rash, ulcers, distal ischemia or gangrene, and, rarely, livedo reticularis and acrocyanosis. Histologically, monoclonal cryoglobulinemia exhibits vascular dilatation, endothelial swelling and plugging of lumina of vessels with diastase-resistant and PAS-positive hyaline thrombi. Intravascular rouleaux may be seen. Mixed cryoglobulinemia is associated with immune complex-mediated acute LCV.
Cryoglobulinemia
Cryoglobulins are immunoglobulins that precipitate in small vessels at low temperatures and dissolve at high temperatures. Type 1, monoclonal cryoglobulinemia, is associated with lymphoproliferative diseases. Type 2 and 3 (mixed) cryoglobulinemia is associated with hepatitis C infection. Anywhere from 2 to 15% of patients with cryoglobulin develop cryoglobulinemic vasculitis. Trejo et al. found that the most frequent cutaneous feature seen in cryoglobulinemic vasculitis is palpable purpura, and less commonly seen is Raynaud phenomenon, a skin rash, ulcers, distal ischemia or gangrene, and, rarely, livedo reticularis and acrocyanosis. Histologically, monoclonal cryoglobulinemia exhibits vascular dilatation, endothelial swelling and plugging of lumina of vessels with diastase-resistant and PAS-positive hyaline thrombi. Intravascular rouleaux may be seen. Mixed cryoglobulinemia is associated with immune complex-mediated acute LCV.
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