White fresh skin, also known as moss skin, northern fresh skin, and smelly root skin. Recorded in the "Shennong's Classic of Materia Medica". It is the root skin of the plant Dictamnus dasycarpus Turcz. of the Cruciferae family. The roots are dug in spring and autumn, the mud and coarse skin are removed, and the root skin is peeled and dried.
[Processing method] "Remove the core" according to "Treatise on Febrile Diseases". "Remove the stem" according to "Experience Book of Sores and Ulcers". "Remove the bones and clean" according to "Universal Aid". "Rinse with water and remove coarse skin" according to "Introduction to Medicine". Currently, the original medicinal materials are taken, impurities and residual wood cores are removed, washed, soaked, cut into thick slices, and dried.
[Characteristics of the medicinal slices] They are cylindrical, 5-15cm long, and 1-2cm in diameter, with a thickness of 0.2-0.5cm. The outer surface is grayish white or light grayish yellow, with fine longitudinal wrinkles and fine root scars, often with protruding granular points. The inner surface is whitish with fine longitudinal stripes. It is brittle, the cross section is not flat, and it is slightly layered. It has a musky smell and a slightly bitter taste.
[Processing effects] White fresh skin has a bitter and cold taste. It enters the spleen, stomach, and bladder meridians. It has the functions of clearing heat and dampness, dispelling wind, and detoxifying. Processing makes the medicinal material clean, facilitates the dissolution of effective ingredients, and is convenient for compounding and preparation. It is used for damp-heat sores and ulcers, profuse yellow vaginal discharge, eczema, wind rash, scabies, rheumatoid arthritis, and yellow jaundice with red urine. For example, it is used in the treatment of facial nerve paralysis in the Fu Zheng San ("Formulation Specification of Jilin Provincial Hospital") and in the treatment of athlete's foot, eczema, and scabies, etc., in the compound white fresh skin tincture ("National Medical Product Catalog").
[Processing research] White fresh skin was first recorded in the "Shennong's Classic of Materia Medica" and was originally called "White Fresh", listed as a medium-grade herb. In the Song Dynasty, "Treatise on Febrile Diseases" first mentioned the method of removing the core, and there was also a method of "removing the core, washing and roasting" ("Universal Aid"). Later, clean processing and slicing were mostly used, and in the Qing Dynasty, there was still a method of stir-frying with alcohol ("Dui Pei Ben Cao"). In modern times, it is washed with water, soaked, and then cut into slices.
