血管炎杂志

Purpura on the Lower Limb due to Medication

Abstract

Jude Lim

Purpura is a condition of red or purple discolored spots on the skin that do not blanch on applying pressure. The spots are caused by bleeding underneath the skin secondary to platelet disorders, vascular disorders, coagulation disorders, or other causes. They measure 3–10 mm, whereas petechiae measure less than 3 mm, and ecchymoses greater than 1 cm. Purpura is common with typhus and can be present with meningitis caused by meningococci or septicaemia. In particular, meningococcus (Neisseria meningitidis), a Gram-negative diplococcus organism, releases endotoxin when it lyses. Endotoxin activates the Hageman factor, which causes disseminated intravascular coagulation. The DIC is what appears as a rash on the affected individual.