Snapshot A 67-year-old man presents to the clinic with a two day history of a painful rash on his left flank and radiating to his back. This was preceded by a burning pain in the same region several days prior. Patient does not recall any history of childhood exanthems and is not up to date on his immunizations. Vital signs are stable. Physical exam reveals a maculopapular rash in a dermatomal distribution on the left flank and extending into the back. Introduction Classification virus DNA virus enveloped Herpesviridae VSV (HHV-3) Acutely causes chickenpox becomes latent in the dorsal root ganglion reactivation causes herpes zoster or shingles Presentation Most often involves older adults > 50 years of age immunocompromised patients with history of chickenpox Painful skin lesions present in unilateral dermatomal distribution may involve more than one dermatome Lesions progress as follows raised macules/papules on erythematous base blisters or bullae on erythematous base pustules (days 3-4, may become hemorrhagic) crusting lesions (days 7-10, no longer contagious) new lesions forming after 7 days should raise concern for immunocompromised state 20% experience prodromal fevers, headache, malaise, and fatigue 75% experience prodromal neuritis pain in affected dermatome that precedes development of skin lesions 10-15% experience post-herpetic neuralgia Evaluation Diagnosis is clinical and based on the findings of unilateral, painful skin lesions on an erythematous base present in a dermatomal distribution Differential Herpes simplex (HSV) Contact dermatitis Treatment Goals of treatment reduce duration of skin lesions lessen severity and duration of pain related to skin lesions prevent formation of new skin lesions lessen likelihood of progression to post-herpetic neuralgia decrease transmission of virus Treatment should be initiated within 72 hours of onset of skin lesions to achieve optimal outcomes still recommended for those outside the 72 hour window Antivirals are the mainstay of therapy acyclovir 800mg 5x/day reduces duration of symptoms due to dosing regimen, patient compliance is reduced famciclovir 500mg TID equivalent outcomes to valacyclovir valacyclovir 1000mg TID accelerated improvement in acute neuritis when compared to acyclovir otherwise, equivalent outcomes to acyclovir and famciclovir Pain management Prognosis, Prevention, and Complications Prevention herpes zoster vaccine is a live, attenuated virus vaccine vaccination is recommended for immunocompetent adults > 60 years of age vaccination reduces the risk of having shingles by 51% developing post-herpetic neuralgia by 66.5% reduced the duration of symptoms by 61.1% Complications post-herpetic neuralgia (10-15% incidence) secondary bacterial infection herpes zoster ophthalmicus (HZO) involvement of the trigeminal nerve (V1) can be sight-threatening presents with pain/lesions on the eyelids, forehead, nose, and top of the head Wood's lamp exam should be performed on all patients with suspected HZO may show corneal ulceration Ramsay Hunt syndrome triad of unilateral facial paralysis lesions in the external auditory canal ear pain can also have hearing deficits, tinnitus, and vertigo caused by reactivation from the geniculate ganglion affects multiple cranial nerves: V, IX, and X aseptic meningitis encephalitis