What are the complications of herpes simplex virus infection?

Complications of Herpes Simplex Virus Infection

Herpes simplex virus causes a spectrum of complications ranging from localized mucocutaneous disease to life-threatening systemic and neurological manifestations, with severity dramatically increased in immunocompromised patients, neonates, and during pregnancy.

Neurological Complications

Central Nervous System Disease

• HSV encephalitis is the most devastating neurological complication, characterized by inflammation and swelling of the brain with substantial mortality and severe neurocognitive sequelae even with treatment 1
• Temporal lobe involvement is typical for HSV-1 encephalitis, with intracerebral hemorrhage occurring in approximately 27% of CNS HSV cases through vessel disruption within the temporal lobe lesion 2
• HSV-2 meningitis presents with headache, photophobia, fever, meningismus, and CSF lymphocytic pleocytosis with mildly elevated protein and normal glucose 3
• Recurrent lymphocytic meningitis is caused by HSV-2 in 78-84% of cases, representing a rare but significant complication of genital HSV-2 infection 3
• Ischemic stroke occurs as a complication of HSV infection, frequently multifocal and related to large vessel vasculitis, predominantly associated with HSV-2 2
• Cerebral venous sinus thrombosis has been documented as a rare cerebrovascular manifestation of HSV CNS infection 2

Peripheral Nervous System Complications

• Sacral autonomic nervous system dysfunction occurs in approximately 2% of primary first-episode genital herpes cases 4
• Sacral radiculitis can complicate HSV infections, particularly in immunocompromised individuals 5
• Bell's palsy is recognized as a neurological complication of HSV infection 5

Systemic and Visceral Complications

Disseminated Disease

• Disseminated multiorgan HSV infection occurs in approximately 25% of neonatal HSV cases, with encephalitis present in 60-75% of these infants 6
• Pneumonitis requires hospitalization and IV acyclovir therapy as a severe complication necessitating aggressive management 7
• Hepatitis is a recognized visceral complication requiring IV antiviral therapy 7
• Fatal multiorgan failure can occur with disseminated HSV-1, predominantly in immunocompromised patients but rarely documented even in previously unrecognized immunosuppression 8
• Viremia represents systemic spread of HSV infection 5

Neonatal Complications

Clinical Presentations in Neonates

• Neonatal HSV manifests in three patterns: disseminated multiorgan disease (25%), localized CNS disease (35%), or disease limited to skin, eyes, and mouth (40%) 6
• Devastating cutaneous, ocular, and CNS damage can result from neonatal HSV infection 6
• Vesicular rash is present in approximately 80% of neonates with localized skin/eye/mouth disease but only 60% with CNS or disseminated disease, making diagnosis challenging 6
• Cutaneous recurrences occur during the first 6 months after treatment even in successfully treated neonates with skin lesions 6

Transmission Risk Factors

• Primary maternal HSV infection carries the highest transmission risk (30-50%) compared to reactivated infection (0-5%) 6
• Cervical HSV shedding on the day of delivery occurs in approximately 10% of HIV/HSV-2 coinfected women versus 2-3% of HIV-negative women 6
• Prolonged rupture of membranes (>6 hours) increases transmission risk through ascending infection from the cervix 6

Complications in Immunocompromised Patients

HIV-Infected Individuals

• Prolonged and severe episodes of genital or perianal herpes are common, with lesions that may be severe, painful, and atypical 7
• Recurrent or persistent HSV is an AIDS-indicator condition in approximately 6% of pediatric AIDS cases 6
• Frequent recurrences occur in 5-10% of HIV-infected children with primary gingivostomatitis, associated with severe ulcerative disease 6
• Disseminated HSV with visceral involvement including liver, adrenals, lung, kidney, spleen, and brain can occur when primary infection happens during severe immunocompromise 6
• Acyclovir resistance develops more commonly in HIV-infected patients with prolonged antiviral exposure 7

Other Immunocompromised States

• Extensive disease with prolonged duration occurs in patients with malignancy, transplant recipients, and those on immunosuppressive therapy 9
• Highest risk for acyclovir resistance exists in transplant recipients and patients with prolonged antiviral exposure 9

Local and Regional Complications

Mucocutaneous Complications

• Extragenital lesions develop in 20% of patients with first-episode primary genital herpes 4
• Secondary yeast infections complicate 11% of primary first-episode genital herpes cases 4
• Severe ulcerative disease can occur with recurrent episodes in immunocompromised children, with symptoms similar to primary infection 6

Genitourinary Complications

• Dysuria affects 63% of patients with primary first-episode genital herpes 4
• Urethral involvement occurs in 82% of women and 28% of men with first-episode primary genital herpes 4
• Cervical involvement is documented in 88% of women with first-episode primary genital herpes 4

Other Organ Systems

• Esophagitis can occur in HIV-infected children with severe immunocompromise, requiring endoscopy with biopsy for definitive diagnosis 6
• Pharyngeal involvement occurs in 13% of women and 7% of men with first-episode primary genital herpes 4

Superimposed Bacterial Infections

• Sepsis secondary to Streptococcus pyogenes bacteremia has been documented as a complication of primary genital HSV-1 infection even in immunocompetent adolescents 5
• Superimposed bacterial infections represent a recognized complication that clinicians should monitor for during HSV outbreaks 5

Critical Clinical Pitfalls

• Absence of vesicular rash in 40% of neonates with CNS or disseminated disease can delay diagnosis and treatment 6
• Asymptomatic recurrent episodes occur in 25% of cases, facilitating ongoing transmission 4
• Atypical presentations in HIV-infected patients may not follow classic patterns, requiring high clinical suspicion 7
• Delayed recognition of disseminated disease can lead to rapid progression to life-threatening complications requiring immediate IV acyclovir 9