Coptis and Cnidium Powder

Named for its two leading drugs, 黃連 and 蛇床子. Coptis at double the weight of the others is the bitter cold drug for the inflamed oozing scalp, cnidium seed is the parasiticide and antipruritic, gallnut is the astringent that would dry and tighten a weeping crust, and the schizonepeta wash before dressing is proper wound toilet. Three of those four are defensible on their own terms. The fourth is calomel, and it is why this leaf needs a warning rather than a recommendation. 癩頭瘡 is tinea capitis with impetigo, and the chapter is explicit that this formula is for 小兒 — small children. The leaf before it in the section, the 丹心 prescription for 小兒癩頭瘡, puts quicksilver, litharge and alum on the same scalps. **Contains calomel, which is mercury. This must not be prepared.** Mercury applied to the broken, weeping scalp of a small child, in oil, under an occlusive dressing, is absorbed; infants and young children are the group most vulnerable to mercury, and calomel teething powders caused acrodynia in children well into the twentieth century. Tinea capitis needs an oral antifungal; the impetigo needs an antibiotic. — Eui Young (Justin) Chung, L.Ac., Dipl. O.M.