A small amount of pus accumulates in the ear canal of patients with auricular ringworm, which can be directly examined and cultured for bacterial growth. It helps in diagnosis. Mycelium and spores are visible on examination by taking cerumen or scabs with 10% KOH solution. Sometimes a conidial head is visible and culture has fungal growth. In addition to the above tests, the doctor will need to differentiate the diagnosis from auricular ringworm with similar symptoms. There are two symptoms that need to be diagnosed differently from auricular ringworm: 1. Pus accumulation in the external auditory canal Pus may form in the external auditory canal due to a lesion in the external auditory canal itself, or it may accumulate in the external auditory canal due to pus flowing from a middle ear lesion at the perforation of the eardrum. Generally speaking, if the pus is sticky, it is most often due to middle ear disease; if it is not, it is most often due to outer ear disease. External ear diseases include external ear canal boils, diffuse external ear canal infection and external ear eczema, while middle ear diseases are mainly acute and chronic purulent otitis media. 2. Redness, swelling and ulceration of the external ear canal are commonly seen as external ear canal boils and diffuse otitis externa, which are called ear boils and ear sores respectively in Chinese medicine. The former shows limited redness and swelling with obvious pain, protruding like a pepper eye or topped with pus, while the latter shows diffuse redness, ulceration, and more yellowish-white discharge.