Purpura is a skin rash that forms after a person has hemorrhaged into the skin and mucous membranes from the capillaries. The resulting elements of this rash are called petechiae. Purpura can be observed either due to the presence of defects in the capillaries themselves (so-called simple purpura (nonthrombocytopenic purpura)) or due to a decrease in the number of platelets in the blood (thrombocytopenic purpura).
Purpura simplex is usually not a serious condition and can be caused by physical stress, injury, certain medications, or infectious diseases. In such cases, where purpura is caused by a temporary defect in the capillaries, it usually disappears on its own.
Thrombocytopenic purpura is a more serious disease that can occur due to a decrease in the number of platelets in the blood. Platelets are cells that help blood clot, so a lack of them can lead to bleeding. Acute idiopathic thrombocytopenic purpura (AITP) is a childhood disease characterized by the production of specific antibodies in the child's body that destroy platelets in the body. The disease usually goes away over time without any treatment, but in some cases treatment to increase platelet levels in the blood may be required.
Henoch-Schönlein purpura is a rare hereditary disease that is characterized by increased bleeding and the formation of hemorrhages in the skin, mucous membranes and internal organs. This disease is associated with impaired platelet function and can lead to serious complications such as internal hemorrhage.
Overall, purpura is a condition that can occur for a variety of reasons and requires some attention. If you develop an unexplained skin rash or bleeding, you should see your doctor for diagnosis and treatment.