What does "dartrous" mean?

Dartrous: Relating to, or partaking of the nature of, the disease called tetter; herpetic. Dartroud diathesis, A morbid condition of the system predisposing to the development of certain skin deseases, such as eczema, psoriasis, and pityriasis. Also called rheumic diathesis, and hipretism. Piffard.