Advances in the understanding of chondrodermatitis nodularis chronica helices: the perichondrial vasculitis theory.

OBJECTIVES Chondrodermatitis nodularis chronica helicis (CNCH) usually presents as a painful nodule affecting the pinna. The aetiology of the disease is unknown. Several theories have been suggested. We suggest a possible explanation based upon pathophysiological treatment correlations to new histopathological evidence. DESIGN A detailed histopathological review of 16 confirmed cases of CNCH was undertaken by two pathologists, independently and together, using a qualitative grading of arteriolar narrowing. RESULTS Review of cases revealed arteriolar narrowing in perichondrium region of pinna most remote from arterial blood supply, i.e. helix. This has lead to ischaemic changes and death of the metabolically active underlying cartilage with necrosis and extrusion. CONCLUSION This is the first report of specific perichondrial arteriolar changes as the possible cause of underlying cartilage necrosis resulting in CNCH.