A scratch on the hand belongs to a skin scratch disorder called artificial urticaria. Although the exact pathogenesis is not clear, it is likely to be related to the high sensitivity of mast cells to environmental factors. Artificial urticaria is a reaction of windburn and redness that occurs rapidly after scratching, scratching or applying pressure to the skin with force. It is a chronic form of urticaria. People who have dry skin for a long time or suffer from dermatitis or allergies are more prone to artificial urticaria than the general population. People who have the habit of scratching the skin for a long time and those who are chronically stressed and depressed are also more prone to the phenomenon of artificial urticaria. Pathogenic infections such as bacteria, fungi and scabies or the use of certain medications may also trigger the appearance of artificial urticaria. Therefore, once artificial urticaria occurs, it is necessary to pay attention to the hospital in time, under the guidance of the doctor for standardized treatment.