The large crusted lesions of the pustular syphilid are termed pustulo-crustaceous. They occur in the late secondary and in the tertiary periods of syphilis. Their evolution is usually slow and accompanied by fever. The individual lesions vary from one-quarter to one and a half inches or more in diameter. The crusts are yellowish brown, brown or greenish, usually thick or uneven, and either friable or tough. Removal of the crust may expose either an eroded, pussy, secreting surface or a deep, punched-out, unhealthy ulcer.