Fungal disease of the external auditory canal is a fungal infection of the external ear canal. The fungus tends to grow and multiply in warm and humid environments. In mild cases, there are no uncomfortable symptoms. Those with symptoms usually feel unbearable ear itching, ear swelling, and watery or yellowish water. Ear pain and tinnitus (occasional) can occur. This disease is not difficult to diagnose. An outpatient examination may reveal a yellow or white powdery or filamentous material covering the external ear canal and/ or tympanic membrane, sometimes with secretions or scabs in the form of a tube, and the surrounding external ear canal skin may be red, swollen and moist. Patients with tympanic membrane perforation and post middle ear mastoid surgery can have symptoms of effusion, and in severe cases secretions and mold blocking the external ear canal causing more severe hearing loss. We know that fungi like to grow in a humid environment, for example, some patients like to pull out their ears frequently, which causes congestion in the external ear canal; for example, when washing hair and bathing, the external ear canal gets water or retains secretions; for example, the external ear canal is more susceptible to fungal infections when antibiotic solution is used for a long time. Some patients have foot fungus and like to pull out their ears with their feet, so they are prone to external ear canal mycobacteria. And some patients have high humidity in their homes or work environment, which is also one of the susceptibility factors. Therefore, we should pay attention to personal hygiene and ventilation of the surrounding environment, avoid water in the external ear canal and long-term ear drops, and pull out the ear less. We should also seek medical attention when we have discomfort. 2011-October Addendum: Recently, we found that after surgery (including tympanic membrane repair), some patients had mycobacterial infections at their follow-up visits after discharge, and they always had moist, itchy, or even running water in their ears. After asking the summary is as follows: 1, some patients themselves have foot odor (also for mold infection), after surgery because of extra attention to the surgical ear, so nothing to buckle the foot pulling out the ear caused; 2, some people have hand rash caused by work, after pulling out the ear; 3, some people work in a humid environment or home environment, easy to mold growth, 4 someone who does not have foot odor, but family members such as loved ones, parents have foot odor. Living together inevitably leads to contact; 4, students, especially some college students like to wear hiking shoes, sneakers, these shoes are not permeable plus sweaty feet, easy to mold reproduction; 5, college students live in group dormitories, like to wear other people’s slippers, causing cross-infection. So it is recommended that you pay attention to personal habits and hygiene, wash your hands with soap regularly and do not pull out your ears at will.