Petechial rash in meningitis is most characteristic of infection with which organism?

• A. Neisseria meningitidis
• B. Streptococcus pneumoniae
• C. Haemophilus influenzae
• D. Listeria monocytogenes

Answer: (A)

Petechial rash in meningitis points to meningococcemia from Neisseria meningitidis. The endotoxin-driven septicemia causes widespread small vessel damage, producing non-blanching petechiae on the skin and mucous membranes. This feature is classic for meningococcal infection and helps distinguish it from other meningitis pathogens such as Streptococcus pneumoniae or Haemophilus influenzae, which less commonly present with a petechial rash; Listeria meningitis also lacks this characteristic rash. The rash can progress to severe septic shock and Waterhouse-Friderichsen syndrome if not treated promptly.