Purpura just means purple. The term purpura is usually used to refer to a skin rash in which small spots of blood appear on the skin. A purpuric rash is not a disease but it is caused by conditions that result in blood leaking into the skin and other body surfaces.
This is a companion discussion topic for the original article at https://patient.info/allergies-blood-immune/blood-clotting-tests/purpuric-rashes