A relatively common non-neoplastic inflammatory and degenerative lesion that affects the external ear. it is characterized by necrotic changes in the dermis and perichondrium. it usually affects the helix. patients present with a painful nodule that contains a cup-shaped crater filled with necrotic debris, inflammatory cells, and fibrin. it is caused by helmets, headsets, actinic changes, and frostbite resulting in dermal microtraumas. it is often confused clinically with squamous or basal cell carcinoma, and it may recur.