🦠microbiology review

Petechiae

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

Petechiae are small, pinpoint red or purple spots on the skin caused by minor bleeding from broken capillaries. They can be a sign of various underlying conditions, including infections affecting the circulatory and lymphatic systems.

5 Must Know Facts For Your Next Test

  1. Petechiae often indicate a low platelet count (thrombocytopenia) or clotting disorder.
  2. Common causes of petechiae include viral infections like dengue fever, bacterial infections such as meningococcemia, and certain medications.
  3. The presence of petechiae can help differentiate between different types of rashes in clinical diagnoses.
  4. Petechiae do not blanch (turn white) when pressed, unlike some other types of skin rashes.
  5. In the context of sepsis, petechiae can signify disseminated intravascular coagulation (DIC), a severe condition requiring immediate medical attention.

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