Penis & scrotum


Herpes simplex virus

Last author update: 1 February 2010
Last staff update: 14 August 2023 (update in progress)

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PubMed Search: Herpes simplex virus penis

Alcides Chaux, M.D.
Antonio L. Cubilla, M.D.
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Cite this page: Chaux A, Cubilla AL. Herpes simplex virus. website. Accessed September 28th, 2023.
Definition / general
  • Herpesviridae family has at least 8 viruses known to infect man: HSV1, HSV2, Epstein-Barr virus (EBV), cytomegalovirus (CMV), varicella zoster virus (VZV), Human herpesvirus 6 (exanthum subitum or roseola infantum), Human herpesvirus 7 and Human herpesvirus 8 (Kaposi sarcoma associated herpesvirus)
  • Sexually transmitted; spreads by direct contact with lesions
  • Also spreads by asymptomatic shedding when no lesion is apparent
  • Genital region, mouth; also other areas
  • Although historically caused mainly by HSV2, now 5 - 30% of primary outbreaks of genital herpes are caused by HSV1
  • Blisters contain large number of viral particles and are very contagious
Diagrams / tables

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Herpesvirus structure

Clinical features
  • HSV infection is the most common cause of genital ulceration (BJU Int 2002;90:498)
  • Multiple (6 - 10) small (1 - 2 mm) papules and macules, followed by vesicles that rupture and cause painful ulcers, usually at tip of penis or on shaft
  • Atypical presentations include fissures, furuncles, linear excoriations and ulcerations
  • In immunocompromised patients, especially those HIV positive, ulcerations can be deep and persistent
  • Blisters occur around anus in men who have sex with men
  • Usually diagnosed clinically, with confirmation by culture, direct fluorescent antibody, skin biopsy and PCR for viral DNA
  • Primary outbreak: occurs 3 - 14 days after exposure; patients usually asymptomatic but rarely have systemic symptoms of fever, headache, muscle ache, fatigue, swollen and tender lymph nodes
  • After infection, viral genome remains in latent state in nuclei of sensory neurons for life
  • Recurrences: may not occur at all or up to 40 years after primary outbreak and usually milder than initial outbreak
  • Antiviral drugs reduce frequency, duration and severity of outbreaks and asymptomatic shedding
  • Antiviral medications include aciclovir (Zovirax), valaciclovir (Valtrex), famciclovir (Famvir) and penciclovir (Wikipedia: Herpes Simplex [Accessed 29 March 2018])
Clinical images

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Multiple vesicles and ulcerations on surface

Microscopic (histologic) description
  • Multinucleated giant cells with ground glass nuclei due to intranuclear virus
  • More common at interface between ulcerated and nonulcerated areas
  • Intraepithelial vesicles contain rounded acantholytic keratinocytes
  • Keratinocytes show viral cytopathic changes of ground glass nuclei, nuclear molding and multinucleated giant epithelial cells
  • Well defined acidophilic inclusions can also be seen
Microscopic (histologic) images

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Multinucleated giant cells with inclusions (right - vulva)

Positive stains
  • HSV1 or HSV2
Electron microscopy images

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Negative stain

"Fried egg" appearance

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