Why do I have petechiae on my body?

Bleeding spots on the skin—commonly referred to as petechiae (pinpoint, non-blanching red or purple dots), purpura (larger, 3–10 mm lesions), or ecchymoses (larger bruises >1 cm)—arise from spontaneous leakage of blood from small capillaries into the dermis. This occurs when there is disruption in one or more components of normal hemostasis: platelet number or function, coagulation factor activity, or vascular integrity.

Common causes include thrombocytopenia (e.g., immune thrombocytopenic purpura, drug-induced platelet destruction, bone marrow suppression from chemotherapy or infection), platelet dysfunction (e.g., aspirin or clopidogrel use, uremia, myeloproliferative neoplasms), coagulation disorders (e.g., vitamin K deficiency, liver disease, disseminated intravascular coagulation, inherited factor deficiencies such as hemophilia), and vasculitic or inflammatory conditions (e.g., Henoch-Schönlein purpura, systemic lupus erythematosus, cryoglobulinemia). Infections—particularly meningococcemia or Rocky Mountain spotted fever—can cause rapidly progressive petechial rashes due to endothelial damage and microvascular thrombosis. Less commonly, mechanical factors like prolonged coughing, vomiting, or tight tourniquet application may produce localized petechiae via increased venous pressure.

It is essential to assess associated symptoms—including fever, fatigue, mucosal bleeding, joint pain, or neurological changes—as well as medication history, recent infections, and family history of bleeding disorders. Physical examination should evaluate for splenomegaly, lymphadenopathy, jaundice, or signs of systemic illness. Laboratory evaluation typically includes a complete blood count with peripheral smear, prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, and D-dimer if DIC is suspected; additional testing (e.g., platelet function assays, von Willebrand factor studies, bone marrow biopsy) may be warranted based on clinical context.

Any new-onset, widespread, or progressive petechial rash—especially with systemic symptoms—requires prompt medical evaluation, as it may signal a serious underlying condition requiring urgent intervention.