" Hemorrhage-induced purpura is distinguished from this condition as it will not blanch in response to pressure.
The "multiforme" spectrum named for this condition is often considered to contain the horrifying Stevens-Johnson Syndrome. This condition is the defining symptom of the perinatal B19 parvovirus, which is often referred to as the "fifth" in a group of six diseases defined by this characteristic. Diseases that characteristically present with this symptom include Bloom's disease and a (*) Borrelia infection which often results in a form known as "migrans." Hemorrhage-induced purpura is distinguished from this condition as it will not blanch in response to pressure. This symptom indicates the process of hyperaemia as a result of increased vasodilation, and its "malar" form provides the name to a major autoimmune disorder. For 10 points, identify this physical symptom whose forms include the "bull's eye" seen in Lyme Disease and the "butterfly" associated with Lupus, which generally refers to a reddening of the skin.
The "multiforme" spectrum named for this condition is often considered to contain the horrifying Stevens-Johnson Syndrome.
Rashes [or Erythmas, the actual medical term for the only type of rash described in this question]