Petechiae vs Purpura vs Ecchymoses

Extravasation of red blood cells into the skin produces erythematous or violaceous lesions that do not blanch.

• Small lesions (<2 mm) are termed petechiae
• intermediate size (2 mm to 1 cm) are called purpura
• larger lesions are referred to as ecchymoses.

In general:

• platelet disorders produce petechiae
• vasculitis causes purpura that is elevated (palpable purpura)
• coagulation disorders result in ecchymoses that may be palpable.
• The presence of palpable purpura, particularly when accompanied by fever, should raise concern about the possibility of septicemia.

Features of acute, fulminant meningococcemia include

• abrupt onset of fever
• palpable purpura concentrated on the buttocks and lower extremities
• elevated white blood cell count.
• In this clinical setting, thrombocytopenia suggests the possibility of associated disseminated intravascular coagulation.
• prompt institution of antibiotic therapy is indicated.
• Pending confirmation of the responsible organism, a child suspected of having sepsis-induced purpura may be treated intravenously with vancomycin and ceftriaxone.
• If the presence of Neisseria meningitidis is confirmed, intravenous aqueous penicillin G may be substituted.