What is the recurrence rate of genital herpes in a patient with a history of recurrent genital herpes undergoing Intravenous Immunoglobulin (IVIG) treatment for Guillain-Barré Syndrome (GBS)?

Recurrence Frequency of Genital Herpes

Genital herpes recurs very commonly, with approximately 85-95% of patients experiencing at least one recurrence after initial infection, though the frequency varies widely from once every few years to several times per month.

Natural History of Recurrences

Recurrence rates depend heavily on the viral type and time since initial infection:

• HSV-2 genital infections recur in approximately 95% of cases, while HSV-1 genital infections recur in only about 50% of cases 1
• In the first year following newly acquired HSV-2 infection, patients experience a median of 5 recurrences per year, compared to only 1 recurrence per year for HSV-1 2
• Recurrences arise with highly variable frequency: from once every few years to several times per month 3

Temporal Pattern: Recurrences Decrease Over Time

The frequency of recurrences significantly decreases over time in most patients:

• After 6 years of observation, 85.8% of patients had at least one recurrence and 75% had at least two recurrences in the subsequent year, with median time to first recurrence of 68 days 4
• Recurrence rates drop significantly between year 1 and year 2 for patients with newly acquired HSV-1 or HSV-2 infection 2
• Patients followed for more than 4 years experienced a median decrease of 2 recurrences per year between years 1 and 5 2
• One-third of all patients experience a decrease of 2 or more recurrences per year between the first and second years 2

Important Caveats About Variability

Individual patient patterns remain highly unpredictable:

• Despite overall trends toward fewer recurrences, 25% of patients followed long-term had an increase of at least one recurrence in year 5, illustrating significant inter-patient variability 2
• Recurrences are highly unpredictable from patient to patient and time to time 1

Clinical Characteristics of Recurrent Episodes

Recurrent episodes are typically shorter and less severe than primary infections:

• Episodes usually last less than 10 days but may be prolonged by secondary bacterial infection or immunosuppression 3
• Patient-observed recurrent episodes have a mean duration of 5.65 days when including nonlesional prodromes, or 6.83 days when excluding them 5
• Prodromes occur in approximately 59% of episodes, with nonlesional prodromes (symptoms without visible lesions) occurring in about 20% of episodes 5

Special Context: IVIG Treatment and GBS

For patients receiving IVIG for Guillain-Barré Syndrome who have recurrent genital herpes:

• IVIG treatment (400 mg/kg every 4 weeks) was shown to dramatically reduce the frequency of HSV genital recurrences in patients with very high baseline recurrence rates (>15 episodes per year) 6
• IVIG resulted in shorter mean duration and less severe lesions compared to intermittent oral acyclovir 6
• This suggests that IVIG therapy for GBS may actually suppress genital herpes recurrences rather than trigger them, likely through expansion of NK cell populations 6

Asymptomatic Viral Shedding

Transmission can occur even without visible lesions:

• In most cases of genital herpes (80-90%), the disease progresses subclinically but may become symptomatic at any time 3
• Asymptomatic viral shedding occurs and represents a major route of transmission, though it occurs less frequently with HSV-1 than HSV-2 7