Risk of Herpes Meningitis in Individuals with Recurrent Herpes Labialis
The presence of herpes labialis (cold sores) has no diagnostic specificity for HSV meningitis in adults and is merely a marker of critical illness, not a risk factor for developing meningitis. 1
Key Clinical Distinction
In adults with recurrent herpes labialis, there is no established increased risk of developing HSV meningitis. The finding of labial herpes in adults with suspected HSV encephalitis or meningitis is coincidental and reflects concurrent critical illness rather than causation. 1
In children, the relationship differs: Children are more likely to develop encephalitis with primary HSV infection (not recurrent labialis), and labial herpes may be noted during these primary infections. 1 However, this represents primary infection manifestations, not a risk from recurrent cold sores.
Understanding HSV Meningitis Epidemiology
HSV-2 is the predominant cause of HSV meningitis, not HSV-1 (which primarily causes herpes labialis). 1 HSV-2 meningitis is sexually transmitted and represents the most commonly recognized infectious cause of benign, recurrent meningitis. 2
HSV-1 is more commonly associated with encephalitis than meningitis. 1 While HSV-1 causes the vast majority of herpes labialis cases, it rarely causes meningitis in immunocompetent hosts. 1
There is no consistent relationship between genital herpes outbreaks and HSV-2 meningitis episodes. 2 Patients with HSV-2 meningitis rarely have concurrent genital ulcers (only 23% had a history of genital herpes in one cohort), and meningitis episodes occur independently of mucocutaneous recurrences. 2
Clinical Presentation of HSV Meningitis
HSV meningitis presents with headache (100%), photophobia (47%), fever (45%), meningismus (44%), and nausea/vomiting (29%), without the typical vesicular lesions of herpes labialis. 2
CSF findings include elevated protein (mean 156 g/dL), lymphocytic pleocytosis (mean 504 cells/μL), and normal glucose (mean 54 mg/dL). 2
Neuroimaging is typically normal (83%) or shows nonspecific changes (14%). 2
Critical Pitfalls to Avoid
Do not assume that recurrent cold sores increase meningitis risk. The viruses causing these conditions (HSV-1 for labialis, HSV-2 for most meningitis) are distinct, and the anatomical sites of latency differ (trigeminal ganglia versus sacral ganglia). 1, 2
Do not use prophylactic aciclovir or valaciclovir to prevent HSV meningitis in patients with recurrent herpes labialis. There is no evidence supporting this practice, and guidelines explicitly recommend against prophylaxis for recurrent herpes meningitis. 1
Do not confuse HSV encephalitis with HSV meningitis. Encephalitis involves altered consciousness and focal neurological findings, while meningitis presents with meningismus and headache without reduced consciousness in adults. 1
Prognosis and Recurrence
HSV-2 meningitis has an excellent prognosis in immunocompetent hosts, with no reported seizures, neurological disability, or death in extended follow-up (mean 3.4 years). 2
Recurrence of meningitic symptoms is not universal, and when it occurs, it is independent of mucocutaneous HSV manifestations. 2
Chronic meningitis due to HSV is exceedingly rare, with isolated case reports in the literature describing atypical presentations. 3