MEDLINEplus: Purpura
Overview of types of purpura, with photos and links, from the National Library of Medicine (U.S.).

NetDoctor.co.uk: Purpura
General information about purpura, with a photo.

Henoch-Schonlein Purpura
A blood disorder in which blood vessel inflammation leads to bruising under the skin (purpura). It usually occurs in children.

Immune thrombocytopenic purpura
Links to information and resources for immune thrombocytopenic purpura (ITP).

Thrombotic thrombocytopenic purpura
A blood disorder characterized by low platelets, low red blood cell count, and neurological abnormalities.