CDNH is a slow growing painful lesion which may reach a size of 2 to 4 mm. It begins as a nodule over the cartilage folds of the ear and may progress to form a central crust and ulceration. The cause is unknown but CDNH usually occurs on the side the patient sleeps and may be related to trauma. The most common location is on the mid portion of the antihelix.
Treatment is to excise the lesion and underlying inflamed cartilage. Steroid injections have also been advocated but in my experience they have not been successful.