A Case of Cutaneous Arteritis Presenting as Infiltrated Erythema in Eosinophilic Granulomatosis With Polyangiitis Features of the Unique Morphological Evolution of Arteritis as a Diagnostic ClueShiiyama, Rie MD*; Chen, Ko-Ron MD, PhD†; Ishibashi, Masafumi MD*The American Journal of Dermatopathology: November 2019 - Volume 41 - Issue 11 - p 832–834 doi: 10.1097/DAD.0000000000001451 Extraordinary Case Report Buy Abstract Author InformationAuthors Article MetricsMetrics Abstract: Eosinophilic granulomatosis with polyangiitis (EGPA, formerly Churg–Strauss syndrome) is a rare systemic vasculitis affecting small- and medium-sized vasculature, associated with asthma and eosinophilia. Different levels of vasculitis in cutaneous lesions have been observed, including dermal small vessel vasculitis and subcutaneous muscular vessel vasculitis. Although the EGPA-associated small vessel vasculitis described as leukocytoclastic vasculitis can be often found in the documented literature, the features of subcutaneous muscular vessel vasculitis in EGPA-associated cutaneous lesions have been rarely demonstrated clinically and histopathologically in English literature. Herein, we report a case of EGPA involving infiltrated erythema on the extremities, with different stages of cutaneous arteritis characterized by eosinophilic arteritis and granulomatous arteritis in the same affected artery. We present this as a unique diagnostic clue for EGPA. *Department of Dermatology, Nippon Kokan Hospital, Kanagawa, Japan; and †Meguro Chen Dermatology Clinic, Tokyo, Japan. Correspondence: Rie Shiiyama, MD, Department of Dermatology, Nippon Kokan Hospital, 1-2-1 Kokandori, Kawasaki-ku, Kawasaki, Kanagawa 210-0852, Japan (e-mail: email@example.com). The authors declare no conflicts of interest. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.