Final answer:
The term 'petechial rash' refers to the condition characterized by petechiae, small red or purple spots on the skin resulting from blood leakage from damaged vessels, and its plural form is 'petechiae.'
Step-by-step explanation:
The term for the condition characterized by petechiae is 'petechial rash,' and its plural form is 'petechiae.' These are small red or purple spots on the skin resulting from blood leaking out of damaged vessels. This can occur in certain infections like meningococcal meningitis, where a petechial rash is one of the distinguishing features and signifies the presence of tiny blood clots that cause blood to leak into the surrounding tissue. Blood vessel disruption, triggered by virulence factors, can cause petechiae and larger hemorrhagic lesions in more severe cases, potentially leading to shock, disseminated intravascular coagulation, and death.