Dermatographia, also known as artificial urticaria, refers to scratching the skin manually with nails or scratching the skin with blunt objects, and the skin will bulge and present a cord-like mass (medically called this cord-like mass as an air mass scratch). The disease can be divided into two types: simple symptoms. Simple abrasion is a rational physical abnormality of normal people, and about 5% of normal people have this phenomenon. Symptomatic scratches can be divided into immediate and delayed types, both of which are caused by allergic reactions. The common pathogen of the former is penicillin, and this kind of allergy does not necessarily have a drug reaction first. 80% of the patients treated with penicillin were positive in skin scratch test, and some patients were still positive long after stopping penicillin. In addition to penicillin, if the patient has a recent bacterial infection (such as acute tonsillitis, cholecystitis, appendicitis, etc.). ) and insect bites can also cause immediate symptoms of skin scratches. However, the occurrence of delayed symptomatic skin scratches is related to fungal allergy, and antigens are often fungal products, so patients with tinea pedis are prone to delayed symptomatic skin scratches.

Simple skin scratches generally do not need treatment. For symptomatic skin scratches, we must first find the cause and remove the cause as much as possible. For example, patients who are using penicillin should stop using penicillin immediately; People infected with bacteria should be treated with anti-infection; People infected with tinea pedis and other fungi can receive antifungal treatment. Secondly, antihistamines, such as chlorpheniramine and antongding, can be used, which has certain curative effect. In addition, some drugs such as vitamin C and calcium can be used to reduce the permeability of blood vessel wall. It is worth noting that patients with skin abrasions should not be treated with penicillin when they suffer from other infectious diseases.