Eczema occurs in a variety of ways, the specific causes are not yet completely clear, and is related to the joint action of internal and external factors, such as insect bites, food allergies, mental factors, physical factors, etc., which may lead to skin pimples, pimples, redness, swelling, itching, erythema and other symptoms. 1. Insect bites: most patients with eczema are associated with insect bites, such as mosquitoes, lice, fleas, bedbugs, mites and so on. The secretions or saliva of insects can cause irritation to the skin, inducing an allergic reaction that may cause eczema. 2. Food allergy: If you are allergic to seafood, and your diet intake of seafood, such as fish, shrimp, crab, causes a metamorphic reaction, resulting in pimples and papules on the skin. 3. Mental factors: affected by mental factors, such as long-term stress, depression, anxiety, leading to immune disorders, the skin may appear eczema-like changes. 4. Physical factors: everyone has a different physique, and the presence of asthma, allergic rhinitis, urticaria and other allergic diseases is also a major cause of eczema. In addition to this, seasonal factors, disease factors, the body is in a special state, such as menopause, pregnancy, easy to trigger eczema. Skin damage, itching and other symptoms may appear on the exposed parts of the skin. It is recommended to go to the dermatology department of the hospital and use medication under the guidance of the doctor, which can help relieve the symptoms.