Woodcut illustrating the 17th century text Xu Ping waike zhengzong (Orthodox Manual of External Medicine with Commentary by Xu Dachun), from an edition published in 1860 (10th year of the Xianfeng reign period of the Qing dynasty). Lotus seed abscess (lianzi fa ju) refers to a type of abscess shaped like a lotus seed, with a prominent head, which is found on the shoulders or back. If the lesions are raised, red and inflamed and suppurating, the prognosis is favourable; if, however, they are depressed or concave, meaning that this is a Yin condition, the prognosis is unfavourable. The renowned Qing physician Xu Dachun writes in his commentary that, all toxic lesions being 'many-headed' (duotou), the preferred method of treatment is that of 'encircling medication' (weiyao), whereby the medication is applied all around the perimeter of the lesion, omitting the head. This is an external treatment.
