Rhubarb powder applied externally can clear heat, relieve fire and detoxify the body. By applying rhubarb powder externally, it can treat many diseases, such as neurological headache, chronic prostatitis, rosacea, bruises, breast enlargement in women, as well as intractable eczema, frostbite, burns, yellow water sores and bleeding hemorrhoids, ringworm, mumps, wheals, herpes zoster, and cervical erosion. You can mix rhubarb powder and other drugs into a paste and apply it to the affected area. You can also mix rhubarb powder with other medicines and then wrap it in cloth for external application. These are all ways to use rhubarb powder externally, and all of them can achieve the purpose of treating the disease.