"Against a Wen" is an Old English metrical charm and medical text found in the London, British Library, Royal MS. 4A.XIV.
It appears to describe a remedy for ridding oneself of a wen, which is an Old English term for a cyst or skin blemish.
[2] It is also classified within the category of dealing with demon-disease[1] a common element to the charm genre where the perceived demon or spirit is lured out with flattery or threat.
Rather than performing the charm on a person, the patient's body is perceived as the host for an evil spirit in which the ritual attempts to expel.
Aelfric's collection of Old English homilies and saints' lives found in MS li.1.33 in the Cambridge University Library.
His homily on the passion of Saint Bartholomew the Apostle (folios 82r to 91r) documents his condemnation of such practises and features a warning against the use of heathen magic in which he outlines the Christian parameters within which medicinal rituals are acceptable.