Understanding Purpura: Definition and Visible Manifestations
Purpura is a condition characterized by the appearance of red to purplish spots on the skin, resulting from cutaneous hemorrhage due to the rupture of small blood vessels. Unlike other redness, these spots do not disappear under pressure, a key characteristic for diagnosing purpura. Petechiae: very small spots, often clustered, measuring a few millimeters. Ecchymoses: larger, they correspond to more significant accumulations of blood under the skin. Color evolution: progressing from bright red to purple, then to brownish as the lesion heals. Location: classically on the legs, but can appear anywhere on the body.These signs may indicate circulatory problems involving either fragile blood vessels or alterations in blood components. Different Types of Purpura and Their Main Causes
- Purpura comes in several forms, each with a specific origin: Thrombopenic Purpura
- : caused by thrombocytopenia, a decrease in the number of platelets. This decrease can result from insufficient production in the bone marrow, increased destruction (as in autoimmune diseases), or excessive consumption in processes such as disseminated intravascular coagulation. Vascular Purpura
- : caused by inflammation of small blood vessels, often linked to vasculitis, an infection, or an allergic reaction.
- Purpura Fulminans
: a very serious form linked to a severe bacterial infection, particularly with meningococcus or pneumococcus, requiring emergency medical attention.
Henoch-Schönlein Purpura
(or Henoch-Schönlein purpura): often benign, this purpura results from inflammation of the blood vessels associated with a rheumatic disease.
- The diverse causes of purpura underscore the importance of a thorough medical examination to guide treatment. Refining the diagnosis of purpura through clinical and paraclinical examination The diagnosis of purpura relies primarily on a careful examination of the skin lesions and the clinical context. The pressure test, which involves pressing on the spot to see if it whitens, is a key step: purpura does not blanch under pressure, unlike other rashes.
- Inquire about the patient’s medical history: autoimmune diseases, use of anticoagulant medications, recent infections. Look for associated symptoms: fever, joint pain, fatigue, neurological disorders. Examine associated signs: swelling, bleeding in other areas (mucous membranes, urine, stool).Blood tests will complete the diagnosis:
- Platelet count (to detect thrombocytopenia).
- Coagulation tests (INR, aPTT) to assess bleeding disorders. Inflammatory markers and autoantibodies if vasculitis or autoimmune disease is suspected.
Blood cultures if a serious bacterial infection is suspected.
Recognizing the signs of purpura for prompt management.
Typical symptoms associated with purpura are quite diverse: Persistent dark red or purplish spots under the skin. Formation of unexplained bruises and fragile skin lesions.
- Epistaxis (nosebleeds), bleeding gums, and mucosal bleeding.
- Blood in the urine (hematuria) or stool (melena).
- In some cases, fever, general malaise, and symptoms of meningitis, particularly in cases of purpura fulminans. In women, irregular and heavy periods can also indicate a clotting disorder related to purpura.
Careful monitoring of these signs helps prevent serious complications such as tissue necrosis or damage to internal organs.
