Ink and brush drawing from a handwritten copy of the anonymous text Dingchuang yaojue (Essential Art of Boils), executed in 1874 (13th year of the Tongzhi reign period of the Qing dynasty). It indicates the disease location for pian duikou di (boil diagonally opposite the mouth. This occurs at the back of the head, to either side of the occipital bone. It is classed as a disorder of the bladder channel of foot taiyang. The preferred therapy is needling and opening (tiaoci), at locations including bailao (Hundred Labours), i.e. dazhui (Great Vertebra), dihe (Earthly Union), weilü (Coccyx) and zhiyin (Reaching Yin); and internal treatment with chuanlian (i.e. huanglian, Chinese goldthread, rhizome coptidis) Poison-Dispersing decoction and Heart-Covering beverage.
