The purpura corresponds to mini hemorrhages on the level of the skin and the mucous membranes. Blood comes out of the vessels and then stays under the skin and mucous membrane, appearing as red dots, red spots, red lines or bruises. Blemishes do not go away when pressed.

The purpura does not itch. It may be linked to a very serious infection such as meningitis, to a drop in the number of platelets in the blood (in this case we speak of thrombocytopenic purpura).

It can also be linked to an abnormality of the blood vessels (this is called vascular purpura or rheumatoid purpura).

Sometimes purpura is an extreme emergency. Indeed, in case of fever, headache and stiff neck associated with purpura in children, you should call the SAMU. purpura fulminans linked to a meningitis meningococcal. This disease requires the fastest possible treatment. Likewise, in an adult purpura with a spot larger than 3mm associated with fever is an extreme emergency, as it can also be meningococcal meningitis. The antibiotic treatment is set up immediately by the SAMU, even before arriving at the hospital.

In the event of purpura of the skin associated with hemorrhages of the mucous membranes (mouth, eyes, genital mucosa), it is also an extreme emergency and it is also necessary to call the SAMU.

There are several kinds of purpura:

– The purpura thrombopénique:

It is caused by a decrease in the number of platelets in the blood. However, platelets are small elements, smaller than red blood cells, whose role is to prevent bleeding. In the event of a small lesion of a vessel, the platelets clump together and prevent bleeding. When they are very low, the slightest lesion can cause a small bleeding, or sometimes a significant hemorrhage.

Immunologic thrombocytopenic purpura (ITP), most often benign, however, must be managed quickly. Children with the condition usually recover completely, while adults may subsequently suffer from chronic purpura. ITP is a disruption of the immune system that produces antibodies that attack its own platelets. The platelet count drops and the risk of bleeding increases.

Thrombocytopenic purpura can have other causes such as taking certain medications, an autoimmune disease, liver disease, certain viral diseases (HIV, hepatitis B or C) or even an infection with helicobacterpylori (also causing stomach ulcers). Certain blood diseases can also cause thrombocytopenia, not by destruction of platelets, but by a manufacturing deficit in the bone marrow.

– The vascular purpura:

In these purpura, if the blood comes out of the vessels, it is not because of a lack of platelets, but of an attack of the small vessels, inflammatory or infectious attack, related to a virus, a bacterium, a drug or to an allergic reaction of the vessels.

The affected vessels become less tight and allow blood to pass, hence the spots or purpura points.

In children, the most common vascular purpura is rheumatoid purpura, or Henoch-Schönlein purpura, although it can affect all ages. The little ones vesselsconcerned may be, for example, those of the skin, intestines or kidneys. This purpura can cause abdominal and joint pain. Usually rheumatoid purpura heals quickly.

Causes of purpura

The causes of the appearance of a purpura are very diverse. It can be due to an infection, a blood disease, the effect of a drug or an abnormal immune reaction.

Prevalence

Thrombocytopenic purpura affects one in 10000 people. Rheumatoid purpura affects between 10 and 20 in 100000 children.

The diagnosis

He is faced with the presence of red or purple patches or spots that do not disappear under pressure. A blood test allows the platelets to be dosed quickly. It also helps diagnose inflammation.

In case of meningitis-like purpura, the doctor starts treatment immediately before having the test results. This is an emergency.

In idiopathic thrombocytopenic purpura (ITP), the platelets are low but the numbers of red and white blood cells are satisfactory. If the levels of red blood cells and white blood cells are not normal, the doctor will ask for a myelogram, bone marrow examination. This test can detect certain blood diseases.

In the event of signs of rheumatoid purpura (spots, joint pain, etc.), certain tests such as a blood test or urine tests are carried out, the latter allowing to explore the functioning of the kidneys.

Complications

– At the level of various organs:

Purpura linked to immunological disorders, such as rheumatoid purpura in children, can cause lesions other than the skin. They are linked to the same factors, that is, to the blood coming out of the vessels inside the body. These attacks can occur in the kidneys, in the joints (pain, joint swelling), in the digestive system (abdominal pain, vomiting) and more rarely in the lungs, testes, nervous system or bladder.

– Bleeding:

All purpuras can cause mucosal bleeding or internal bleeding related to the same phenomenon as that observed in the skin.

– Necrosis:

This is the destruction of the tissue where the bleeding takes place. For example, necrosis of an area of ​​skin or an internal area where bleeding has occurred.