What is Chondrodermatitis Nodularis Helices?
CNH, also known as an ear corn, is a tender spot usually on the outer part of the ear, known as the pinna.
What causes Chondrodermatitis Nodularis Helices?
The exact cause is not known. Predisposing factors include sun damage, cold exposure, trauma, pressure induced lack of blood flow and occasionally radiotherapy. The concept of “pressure induced lack of blood flow” can be understood as the cause being sleeping at night on the side of the affected ear.
What are the signs and symptoms of Chondrodermatitis Nodularis Helices?
The bumps (nodules) of chondrodermatitis nodularis helices are skin colored to red, dome shaped lesions with scabbing. Surrounding inflammation may be seen. The majority of lesions occur on the upper helical rim or the middle to lower anti-helical rim. These sites often correspond to the outermost portions of the pinna. The lesions are often exquisitely tender to touch and sleeping on side of the affected ear may be impossible.
What are the risk factors for CNH?
Risk factors include: cold exposure, significant sun damage, and local trauma.
How common is CNH?
This is most common after age 40, with 94% of cases between 50 and 80 years. Both men and women are affected. Chondrodermatitis nodularis helices typically only affects one ear, only 6-10% of patients are affected on both ears.