Eczema behind the ears is rotten and is clinically common in the following diseases: 1. Eczema behind the ears is very common and mainly occurs in children and patients with allergies. Because this area is very humid, it is prone to eczema-like changes, and patients often scratch their ears, which can lead to localized eczema infections. The fusion of eczema and infection can easily lead to necrosis of the local mucous membrane and necrosis of the skin and other related manifestations. In this case, it is recommended that the patient go to a dermatology or ENT clinic as soon as possible, where anti-eczema creams can be applied and oral antihistamines can be taken for symptomatic treatment. 2. Some patients have sebaceous cyst infections behind the ears, and once the cysts break down locally, local erosions and ulcers can form. In this case, it is recommended to go to an ENT clinic and let the doctor do local debridement and disinfection, and change the medication daily for anti-inflammatory treatment.