ABSTRACT
Vasculitis mimics include conditions that may or may not result in true vascular inflammation (“vasculitis”) but present similarly to the defined primary systemic vasculitides. The chapter would also attempt to make note of key categories of disease that may mimic the primary vasculitides, focusing on a few important entities in each category. There is a wide variety of conditions that can mimic vasculitis clinically, radiologically, and on histopathology. Important causes of vasculitis mimics are malignancies, endocarditis, drugs, infections, collagen disorders, and antiphospholipid antibody syndrome. A wide variety of infections caused by bacteria, viruses, and fungi may have vasculitis as an initial clinical presentation. The insult to the vasculature can either be by direct invasion of the endothelium by the organism or because of immune-mediated hypersensitivity response, mainly type III. Embolic conditions like Sneddon syndrome and cholesterol embolism can result in conditions mimicking vasculitis. A wide variety of drugs may result in mimics of vasculitis or indeed can cause a true vasculitis. Common drugs implicated are minocycline and hydralazine and carbamazepine. A large variety of malignancies are associated with vasculitis. These are mostly hematological malignancies rather than solid tumors. It is important to diagnose these conditions and distinguish them from vasculitides.
