Cocaine-induced pseudovasculitis.

Pseudovasculitis is a disease process that mimics the presentation and possibly the laboratory findings of true vasculitis. However, biopsy specimens do not reveal the typical histopathologic findings expected in vasculitis. One often overlooked cause of pseudovasculitis is cocaine use, which has been described in case reports to cause aggressive nasal destruction and various skin lesions and thus has been confused with Wegener granulomatosis or leukocytoclastic vasculitis. Unfortunately, serologic tests such as antinuclear antibody or antineutrophil cytoplasmic antibody cannot reliably differentiate between these entities. We describe a patient who presented with what was believed to be Wegener granulomatosis affecting the skin and upper airway. However, findings from repeated biopsies did not support this diagnosis, and the only unifying diagnosis was cocaine-induced pseudovasculitis. The ability to recognize and differentiate between true vasculitis and pseudovasculitis is essential for the clinician because treatment options are radically disparate.