Itchy nodular rash is a chronic inflammatory skin disease with nodules as the main lesion, accompanied by intense itching. It is generally believed that patients are mostly allergic, and the occurrence of itchy rash may be related to various factors such as mosquito bites, abnormal body metabolism, gastrointestinal dysfunction, and endocrine dysfunction. The disease is usually found on the extremities, especially on the extensor side of the lower legs, and in severe cases it can involve the whole body. The initial occurrence of the papules in the insect bites, gradually forming hemispherical nodules, soybean or bean-like size, the top of the keratinization is obvious, warty appearance, rough surface, firm to the touch, reddish brown or dark brown. The itchy rash is mostly isolated and scattered, but in heavy cases it can also be dense into patches or longitudinal arrangements. The number of itchy rashes is variable, usually several to dozens or more, and in severe cases, up to hundreds. Due to the intense itching, patients often scratch, resulting in epidermal peeling, bleeding or crusting, pigmentation and hypertrophy of the skin around the nodules, and moss-like changes, the duration of the disease usually varies from several months to several years. Because of the difficulty of general treatment, and the intense itching of the rash makes patients can not help scratching, so the disease often persists, seriously affecting the mood and daily work and life of patients. High-pressure injection is a new and different method from traditional injection. The traditional injection method involves sticking a needle into the nodule and then slowly pushing it in, which is painful for the patient. Due to the hard texture of the nodule, it is difficult to inject the medicine evenly, and sometimes the pressure of the push injection may be too high and the syringe needle joint may collapse, resulting in a waste of the medicine. We use a special imported high-pressure syringe to avoid the problems of leakage and uneven injection due to high pressure. This high-pressure syringe has no needle, and the drug is injected into the patient evenly by a high-pressure jet by compressing air with a hand-held lever. Each nodule is injected in seconds, and each injection takes only a few minutes to ten minutes, and the injected drug is immediately visible in the nodule. There is little pain for the patient and the procedure is quick and painless for the doctor. The patient is usually cured after 1 or 2 treatments.