Itching behind the neck may be caused by atopic dermatitis, neurodermatitis, insect bite dermatitis or ringworm. 1. Allergic dermatitis: some people are allergic to pollen, dust mites, animal fur and other substances that can easily lead to allergic dermatitis, so the back of the neck will appear red, swollen and itchy symptoms; 2. Neurodermatitis: neurodermatitis is usually associated with emotional tension and anxiety, mental stress or local friction, the main symptom is that there will be localized pimples and itching and other manifestations, there will be hyperpigmentation phenomenon; 3. insect bite dermatitis: if the back of the neck by insect bites, such as mites or mosquito bites, resulting in insect bite dermatitis, will also appear red, swollen, itching symptoms; 4. Ringworm: ringworm is usually associated with wearing clothes that are not breathable or are too tight and contacting other ringworm patients’ clothes, etc. The main symptom is that there will be localized blisters and papules, and will be accompanied by itching phenomenon. The back of the neck itch, it is recommended to go to the regular hospital for examination, a clear diagnosis, and actively follow the doctor’s advice to adopt the appropriate solution, so as not to delay the condition.