The disease belongs to the category of "Xuan'' erchuang" (periotic sore) in TCM according to its clinical manifestations. The cause of the disease is mainly related to pathogenic wind, heat and dampness at the acute stage and blood deficiency at the chronic stage. When the ear is invaded by pathogenic wind, heat and dampness, skin swelling and ulceration will occur, causing acute onset in most cases; when blood deficiency generates wind and transforms into dryness, loss of nourishment of otic skin will arise, giving rise to chronic onset on most occasions. This is the pathogenesis of eczema.

According to the theory of traditional Chinese medicine, there are some patterns of syndrome that lead to eczema of external ear.
1. Syndrome of wind, dampness and heat
2. Syndrome of dampness and heat of the liver and gallbladder    
3. Syndrome of blood deficiency transforming into dryness