Itchy bumps and itchy skin can be caused by artificial urticaria, atopic dermatitis, eczema and other skin diseases. 1. Artificial urticaria: The cause of artificial urticaria is unknown and may be related to emotion, exercise and frequent scratching. If the skin is scratched, rubbed, or cut with the tip of a blunt, hard object, raised bumps may appear, perhaps accompanied by itching. 2. Atopic dermatitis: The cause of atopic dermatitis is unknown and may be related to immune abnormalities, abnormalities, and environmental factors. It is characterized by dry skin, erythema, papules and intense itching. If the skin is scratched, bumps may appear. 3. Eczema: The cause of eczema is not yet clear, and may be related to factors such as the environment, allergens and abnormal immune function. Trauma, skin infections, and damage to the skin barrier may also trigger eczema. The main manifestations are erythema, edema, papules and itching. There are many reasons for itchy bumps when scratching the skin, so it is recommended that patients seek medical examination to clarify the cause of the disease and treatment under the guidance of the doctor.