Chondrodermatitis nodularis helicis

To the Editor: In the May issue, Maggie So and Randall Edson¹ reported on an older man with a central crust over an ulcerated nodule on the left ear, diagnosed as chondrodermatitis nodularis helicis (CNH) based on the clinical findings. We have two suggestions for the diagnosis and management of CNH.

First, auricular granuloma annulare (AGA) should be considered in the differential diagnosis because it has a clinical presentation and location similar to CNH. AGA commonly presents as multiple, asymptomatic, unbroken nodules on unilateral or bilateral ears, although occasionally a solitary crusted nodule with mild tenderness may be present.² The main difference is that the pathological features of AGA show dermal collagen degeneration, mucin deposition, and either a palisaded or interstitial histiocytic infiltrate. Typical pathological findings include a nodule of degenerated homogeneous collagen surrounded by vascular granulation tissue with an overlying acanthotic epidermis, a central ulcer, inflammation and fibrosis of the underlying perichondrium, and degenerative cartilage.

Another concern is that some patients with CNH may have other associated chronic inflammatory and autoimmune diseases, such as polymyalgia rheumatica, psoriasis, rheumatoid arthritis, CREST syndrome, vitiligo, and chronic dermatitis.³ Therefore, careful history-taking, physical examination, and some targeted laboratory tests are still necessary for the patient with CNH.

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