Snapshot A 60-year-old man presents to an urgent care clinic for a rash on his right arm. He reports that this rash suddenly occurred about 1 day ago. He has been in 10/10 pain from this rash. He reports that he had chickenpox during his childhood and that his physician had recommended that he receive a shingles vaccine; however, he had not had a chance to do so. He has not been sleeping well, as he is currently going through a divorce. On physical exam, there is a vesicular rash in a dermatomal distribution on his right upper arm. He is sent home with the appropriate treatment. 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 Epidemiology demographics herpes zoster in elderly population chicken pox in children encephalitis and pneumonia in the immunocompromised men > women risk factors immunosuppression advanced age previous infection with VZV 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 Prevention herpes zoster recombinant vaccine adults > 50 years of age live vaccine adults > 60 years of age chickenpox live vaccine adults and children 1 year or older Prognosis complete healing may take more > 1 month chickenpox is often self-resolving in children Presentation Herpes zoster painful unilateral vesicular/pustular skin eruption along a single dermatome does not cross midline preceded by prodrome of itchiness or tingling at the site 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 Chicken pox asynchronous vesicular rash very itchy but not painful starts on the head and trunk and spreads to the extremities eventually develops a crust fever and malaise Studies Labs Tzanck smear positive if multinucleated giant cells are seen 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 for chickenpox, treatment is centered around symptomatic relief Conservative soothing creams indication immunocompetent patients with chickenpox Medical oral antivirals indications all patients with shingles immunocompromised patients with chickenpox 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 or keratitis from herpes zoster opthalmicus