A rash, usually caused by tertiary syphilis, first manifested by large elevations of the epidermis filled with a clear, bloodstained, turbid, or purulent serum. The bulla bursts and allows some fluid to escape. As it desiccates, it is covered with a crust that dries, accumulates new layers, and becomes covered with greenish-brown scales, sometimes to a depth of ½ in (13 mm). It is the thickest of all syphilides and presents the most extensive ulcerations. The condition is treated with antisyphilitic antibiotics,
A skin condition typically observed during the third stage of syphilis, marked by the development of sizable blisters and scabs.