Purpura is a condition where purple, bruise-like spots appear on the skin, inside the mouth, or on the organs. This occurs when blood vessels begin to leak and blood collects beneath the skin. Spots may be large and resemble bruises, or small and rash-like.
There are two types of purpura, defined by an individual's platelet count. Platelets are tiny molecules in the blood that give the blood its clotting properties. Those with purpura and normal platelet levels have a condition called nonthrombocytopenic purpuras, while those who also show lower than normal levels of platelets have thrombocytopenic purpuras. Acute cases are short term and last less than six months, while chronic cases last more than six months.
The spots themselves have different names, depending on the size and appearance of the spots. Small spots that resemble a rash are called petechiae. Large spots that look like bruises are called ecchymoses.
Typically, there are other symptoms that go along with the distinctive spots on the skin. Individuals with this condition often have the same spots on the inside of the mouth and gums. They are also prone to nosebleeds and dramatic bleeding during visits to the dentist. Women may have heavier and more difficult menstrual cycles than typical.
Causes vary based on the type of purpura individuals are diagnosed with. Nonthrombocytopenic conditions can be caused by medications or drugs that affect the function of platelets, inflammation of blood vessels, congenital rubella, or congenital cytomegalovirus. Woman can also develop this type because of the pressure changes in the body when they go through childbirth. Thrombocytopenic purpura can be caused by hemangioma, meningococcemia, or by blood-thinning drugs that stop platelets from forming. Infants can also be susceptible to this type, especially if the mother has the same condition.
On the most basic level, the condition is caused by a faulty autoimmune response by the body. When correctly functioning, the body's immune system attacks intruding viruses and helps prevent sickness. It is not known why, but occasionally the body also begins to destroy platelets as it would destroy intruding cells. When this happens, the blood's natural ability to clot decreases and leaks form in the blood vessels.
Purpura is not generally life-threatening. It is possible that bleeding in the brain can occur from leaking blood vessels; this is extremely rare but can also be deadly. In many cases, this condition goes away on its own within weeks or months of beginning. In more severe cases, medication or surgery can be used to regulate it, although individuals can live comfortably with the condition for decades.