Purulent meningitis

Definition: A form of bacterial meningitis characterized by the presence of pus in the subarachnoid space.

Features:

Intense neutrophilic (polymorphonuclear) inflammatory response

Thick exudate in CSF

Turbid or cloudy CSF appearance

CSF findings:

↑↑ White blood cells (neutrophils)

↓ Glucose (hypoglycorrhachia)

↑ Protein

High opening pressure

Usually caused by: pyogenic bacteria (e.g., S. pneumoniae, H. influenzae, N. meningitidis)

In short: Meningitis is the umbrella term.

Purulent meningitis is a severe, bacterial subtype with pus formation and high inflammatory burden.