Snapshot A 27-year-old G3P0A2 presents to the outpatient clinic at 15 weeks' gestation and complains of exquisite vulvular pain and blisters. She reports that she has experienced several similar episodes for the past 5 years. On examination, you find multiple, painful vesicles on her left labia minora. You recall that she had a positive chlamydial culture on her first prenatal visit that was treated with erythromycin tablets. Introduction Herpes simplex virus is an infectious pathogen that presents in two distinct subtypes HSV-1 produces oral-labial lesions (mucous membranes) HSV-2 produces genital lesions (skin) TORCH infection (Toxoplasmosis, Other [Syphilis], Rubella, CMV, and Herpes) Can result in significantly adverse effects on the fetus, neonate, or both does not increase the risk of congenital malformations infectious sequelae are possible Primary infection transmitted by direct contact Spreads via epidermal cells that fuse forming "multinucleated giant cells" Virus remains dormant in local nerves reactivation occurs in unilaterally in areas innervated by these nerves mechanism for reoccurrence is unclear Symptomatic HSV infection for > 1 month may be considered an AIDS-defining illness Epidemiology Common in young adults who do not practice safe sex If mother has active vaginal infection, child has 50% chance of transmission Presentation Symptoms mother presents with multiple, very painful, vesicular, genital ulcers infected infant presents with vesicles seizures respiratory distress meningitis encephalitis impaired neurologic development Physical exam primary herpes infection generally symptoms last longer and are more severe HSV-1 in infancy widespread, severe herpetic gingivostomatitis with oral erosions eczema herpeticum occurs when an infant with preexisting eczema develops a disseminated HSV infection. Can be life-threatening and requires immediate IV acyclovir in adults oral-labial lesions (usually mucous membrane involvement) HSV-2 less common in infancy in adults bilateral, vesicular erosions edema lymphadenopathy recurrences oral herpes "cold sores" vesicular cluster on crusted, erythematous base often triggered by sun exposure and fever or illness genital herpes less pain than primary infection recur unilaterally as vesicular cluster on erythematous base STUDIES Tzanck smear may provide presumptive diagnosis VZV appears similar to HSV on Tzanck smear Viral culture slow but may yield definitive diagnosis Antibody staining confirms diagnosis Differential Varicella zoster virus, other TORCH infections DIAGNOSIS Diagnosis is based primarily on clinica observations and patient history Treatment Prevention Avoid skin-to-skin contact with active, shedding lesions Practice safe sex Cesarian delivery indicated if mother has active, shedding genital lesions Medical management oral or IV acyclovir first-line therapy in most cases IV usually reserved for severe cases or in immunocompromised hosts suppressive therapy daily oral acyclovir may be indicated in some patients usually reserved for patients with > 6 outbreaks annually indicated in patients with erythema multiforme topical therapy acyclovir ointment has proven effective in reducing duration of viral shedding does not prevent recurrence Complications Recurrence is expected, lesions can cause psychological/social anxiety in patients Prognosis Very good to excellent in healthy adults Outcomes in infants born with herpes vary widely according to symptoms