1. Vagrants' disease or a parasitic melanoderma or excoriations and melanoderma caused by scratching the bites of body louse; pediculus corporis: "The street health clinic often saw patients suffering from morbus errorum as a result of body lice.
2. Discoloration of the skin in people who are subject to louse bites over long periods of time: "The medical clinic developed a useful cream to ease the suffering of people with morbus errorum on their bodies."