Neurodermatitis, also known as chronic simple lichen, is a common chronic inflammatory skin disease characterized by paroxysmal severe itching and lichenoid skin changes due to nervous dysfunction. The causes of the disease may be related to neuropsychiatric factors such as irritability, overthinking, tension, depression, fatigue, and poor sleep. It is also associated with gastrointestinal dysfunction and endocrine disorders. Additionally, local skin irritations such as friction from stiff collars, exposure to chemicals, infection sites, soaking in sweat, and sun exposure are related, as well as diet, including alcohol consumption, and the avoidance of spicy or stimulating foods like chili peppers, and allergenic foods such as crabs and other seafood. These factors can all contribute to the development of neurodermatitis, which is not related to any deficiency in the body.