A pimple on the body when it is scratched is called dermatographia, also known as artificial urticaria. There are two types of skin scars, one is called simple skin scars, mostly seen in women, which is a physiological abnormality, the symptoms of which are the appearance of a windy path after the skin has been scratched by nails or other blunt objects, there is no itching or other discomfort, and generally no treatment is needed. The other is symptomatic dermatomycosis, which is common in young people with allergies and is an allergic reaction to the blood vessels of the skin. People with this type of skin scratching often feel itchy skin for no apparent reason and are left with marks after scratching with nails or other blunt objects, which disappear within a few hours. The allergens that usually cause skin scarring are drugs such as penicillin and serum-based products, as well as bacteria, fungi, plant-based proteins, and animal-based proteins. The metabolites of various types of fungi that cause tinea pedis often act as strong allergens, and the body absorbs them and an antigenic antibody reaction occurs, and skin scarring can occur. Other external factors, including diet and inhalants, are also common causes. Therefore, in order to cure cutaneous scratches, the first step is to find the allergen, and only when the cause is found can the underlying problem be solved.