Infectious colitis


Last author update: 1 February 2014
Last staff update: 3 April 2023 (update in progress)

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PubMed Search: HSV (herpes simplex virus) colitis

Lili Lee, M.D.
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Cite this page: Lee L. HSV. website. Accessed September 21st, 2023.
Definition / general
  • Painful discrete ulcers, vesicles or pustular lesions in distal rectum or perianal skin
  • Diagnose with viral culture
  • > 90% of worldwide population is seropositive for HSV by age 30, but HSV colitis is rare (JAMA 2006;296:964)
  • Associated with immunocompromise and idiopathic inflammatory bowel disease
  • Primary HSV infection causes mild/asymptomatic oral labial (usually HSV1) or genital infections (usually HSV2) in immunocompetent patients
  • Latent HSV persists in sensory nerve ganglia
  • In immunocompromised patients, HSV infection can lead to systemic infections
  • Patients on immunosuppressive agents (ie. corticosteroids, azathioprine, cyclosporine, tacrolimus, or methotrexate) are at increased risk
Clinical features
  • Symptoms are similar to colitis of other causes and include watery or bloody diarrhea, fever, abdominal pain, nausea, fatigue, and weight loss
  • Symptoms of inflammatory bowel disease may also be present if there is concomitant disease
  • Immunohistochemical stain with anti-HSV is available for tissue diagnosis
  • Serum HSV IgG and IgM immunoglobulin assays
  • Detection of HSV DNA by PCR in colonic biopsies is more reliable due to high seropositivity of HSV worldwide
  • Viral cultures have slow turn around time
Case reports
  • No vaccination is available for HSV
  • Antiviral therapy with acyclovir
Gross description
  • Painful discrete ulcers, vesicles or pustular lesions in distal rectum or perianal skin
Microscopic (histologic) description
  • Ulceration with neutrophils in lamina propria, cryptitis, crypt abscess, multinucleated giant cells, inclusions in anal transition zone epithelium and perianal skin
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