These spots of blood under the skin, called purpura, are caused by vasculitis. They do not turn white with pressure (non-blanchable). In this particular case, the purpura are associated with an underlying disorder affecting the structure of the blood vessel walls called collagen-vascular disorder.
Review Date 4/8/2019
Updated by: Gordon A. Starkebaum, MD, MACR, ABIM Board Certified in Rheumatology, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.