acne: [19] It is ironic that acne, that represents a low point in many teenagers’ lives, comes from acme, ‘the highest point’. The Greeks used akme, which literally meant ‘point’, for referring to spots on the face, but when it came to be rendered into Latin it was mistransliterated as acnē, and the error has stuck. (Acme comes, incidentally, from an Indo-European base *ak- ‘be pointed’, and thus is related to acid, edge, and oxygen.) => acid, acme, edge, oxygen
1813, from Modern Latin, from aknas, a 6c. Latin clerical misreading of Greek akmas, accusative plural of akme "point" (see acme). The "pointed" pimples are the source of the medical use.
