Snapshot A 45-year-old woman presents to the emergency room for a rash on her face. She reports that this rash started as a small flat red rash yesterday but progressed to a very painful rash. She also reports some blurry vision in her right eye. She has a past medical history of lupus and is on long-term steroids. On physical exam, she has an extensive vesicular rash on the right side of her face involving her nose and eyes. She is admitted into the hospital for antiviral therapy, and ophthalmology is consulted. Introduction Classification varicella-zoster virus (VZV) an enveloped, linear double-stranded DNA virus also known as human herpesvirus-3 transmitted via respiratory secretions direct contact with skin lesions causes chickenpox, herpes zoster (shingles), encephalitis, meningitis, and pneumonia Prevention herpes zoster recombinant vaccine adults > 50 years of age live vaccine adults > 60 years of age Epidemiology Demographics herpes zoster in elderly population encephalitis and pneumonia in the immunocompromised men > women Risk factors immunosuppression advanced age previous infection with VZV ETIOLOGY Pathogenesis the virus infects T-cells the virus is often latent in the dorsal root ganglia or trigeminal ganglia reactivation of the latent virus causes herpes zoster often precipitated by immunocompromise or stress Presentation Symptoms preceded by prodrome of itchiness or tingling painful rash Physical exam painful unilateral vesicular/pustular skin eruption along a single dermatome does not cross midline may involve the eye herpes zoster opthalmicus distribution of cranial nerve V may involve the ear Ramsay-Hunt syndrome or herpes zoster oticus distribution of cranial nerve VII Studies Labs Tzanck smear multinucleated giant cells polymerase chain reaction direct fluorescent antibody staining Making the diagnosis most cases are clinically diagnosed in atypical cases, laboratory examination may be useful Differential Herpes simplex virus distinguishing factor typically does not present in a dermatomal fashion Contact dermatitis distinguishing factor typically is more itchy than painful Treatment Management approach for herpes zoster, antivirals are first-line therapy Medical oral antivirals indications all patients with shingles drugs valacyclovir famciclovir acyclovir intravenous antivirals indication patients with visceral or central nervous system disease drugs acyclovir analgesics indication all patients drugs do not give aspirin for risk of Reye syndrome Complications Disseminated disease in immunocompromised patients often involves the viscera Post-herpetic neuralgia incidence very common Fetal complications blindness scarring limb hypoplasia Vision loss, corneal anesthesia, and keratitis from herpes zoster opthalmicus Prognosis Complete healing may take more > 1 month