By reading Formulas for Fifty-two Diseases（《五十二病方》）

Treatise on the Origins and Manifestations of Various Diseases（《诸病源候论》） and other related classics

it is found that Hu Huo Syndrome（狐惑病） is similar with chancre in the description of the disease symptoms as well as the writing styles; therefore

it is inferred that these two are the same disease but with different names; both of them follow the basic principle of "the sores and ulcers are formulated due to the corrosion by insects". The either red

blackish or white complexion of Hu Huo Syndrome and the chancre involving the five organs are homologous. Yu（蜮）

a mythical creature

is originally a pest that eats grains; Hu Huo changed into Hu Yu is in accordance with the nomenclature of stem borer diseases in the Formulas for Fifty-two Diseases. Simultaneously

yin and yang toxin recorded in Essentials from the Golden Cabinet（《金匮要略》） is analyzed under the basic metaphorical horizon that "sores and ulcers are formulated due to the corrosion by insects"

showing that the presence or absence of yin and yang toxin pus and blood is actually inferring whether there is insects corrosion or not

and Xionghuang（Realgar） and Shujiao（Pericarpium Zanthoxyli） in Shengma Biejia Decoction（升麻鳖甲汤） is applied to kill insects. Hu Yu Syndrome

chancre

Xi Shui Toxin（溪水毒） and stem borer disease

to a certain degree

all reflect the pathogenicity of "insects corrosion"

which is a common metaphor used by the ancients to describe sore and ulcer diseases.