Home > Colon > Sexually transmitted infectious colitis / proctitis

Colon

Infectious colitis

Sexually transmitted infectious colitis / proctitis


Charles H. Wang, M.D.
Gillian L. Hale, M.D., M.P.H.

Last author update: 27 November 2024
Last staff update: 27 November 2024

Copyright: 2003-2024, PathologyOutlines.com, Inc.

PubMed Search: Sexually transmitted infectious colitis / proctitis

Charles H. Wang, M.D.
Gillian L. Hale, M.D., M.P.H.
Table of Contents
Syphilis | Lymphogranuloma venereum | Gonorrhea | Herpes simplex virus | Board review style question #1 | Board review style answer #1 | Board review style question #2 | Board review style answer #2 | Board review style question #3 | Board review style answer #3 | Board review style question #4 | Board review style answer #4 | Board review style question #5 | Board review style answer #5 | Board review style question #6 | Board review style answer #6 | Board review style question #7 | Board review style answer #7
Cite this page: Wang CH, Hale GL. Sexually transmitted infectious colitis / proctitis. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/colonsexuallytranscolitis.html. Accessed December 31st, 2024.
Syphilis
Definition / general
  • Syphilitic proctocolitis: rare disease of the colon and rectum caused by bacterial spirochete Treponema pallidum subspecies pallidum (herein referred to as T. pallidum)

Essential features
  • Acquired by direct intimate contact with an infectious lesion
  • Presents as mucosal ulceration, diffuse proctitis mimicking inflammatory bowel disease (IBD) or mass mimicking malignancy
  • Florid lymphohistiocytic and plasmacytic inflammation with prominent lymphoid aggregates on mucosal biopsies
  • Spirochetes highlighted by T. pallidum immunohistochemistry
  • Associated with other sexually transmitted infections (e.g., chlamydia, gonorrhea)

Terminology
  • Syphilitic proctocolitis; for syphilis, lues and Cupid disease

ICD coding
  • ICD-10
    • A51.1 - primary anal syphilis
    • A51.3 - secondary syphilis of skin and mucous membranes
  • ICD-11
    • 1A61.1 - primary anal syphilis
    • 1A61.3 - secondary syphilis of skin or mucous membranes

Epidemiology

Sites

Pathophysiology
  • Direct contact with active primary or secondary lesions (Clin Microbiol Rev 2006;19:29, Clin Microbiol Rev 2005;18:205)
  • T. pallidum spirochetes infect dermal microabrasions or intact mucous membranes
  • Inoculation site develops painless chancre ~3 weeks postexposure, resolves spontaneously
  • Wide hematogenous dissemination of organisms from the primary site of contact
  • Strong early humoral and cell mediated immune response with generalized lymphadenopathy
  • Secondary stage, 6 - 8 weeks postexposure, with disseminated mucocutaneous rash on trunk and extremities, palms and soles of feet
  • Tertiary stage, untreated progressive inflammation leads to granulomatous tissue and bone destruction (gummas)
    • 10% develop cardiovascular involvement (syphilitic aortitis)
    • Invasion of the central nervous system (CNS) can lead to meningovascular syphilis, involvement of spinal cord causes tabes dorsalis (sensory ataxia in lower extremities)
  • Congenital syphilis: can be transmitted from the bloodstream to developing fetus during pregnancy

Etiology
  • Treponema pallidum subspecies pallidum, Gram negative spiral shaped bacterium
  • Differentiated from nonvenereal pathogenic treponemes (T. pallidum subspecies endemicum [bejel], T. pallidum subspecies pertenue [yaws] and T. carateum [pinta])

Diagrams / tables

Images hosted on other servers:
Progression of syphilis serology

Progression of syphilis serology



Clinical features
  • Symptoms (Open Forum Infect Dis 2021;8:ofab157)
    • Hematochezia
    • Anal pain
    • Abdominal pain
    • Tenesmus
    • Mucous discharge
    • Diarrhea
    • Constipation
  • Most common physical exam findings (Open Forum Infect Dis 2021;8:ofab157)
    • Rectal mass
    • Lymphadenopathy
    • Rash
  • 4 clinical stages: primary, secondary, latent, tertiary (J Pathol 2006;208:224, Clin Microbiol Rev 2006;19:29)
    • Primary (2 - 6 weeks postcontact): painless chancre and localized inguinal adenopathy
    • Secondary (4 - 10 weeks postinfection): maculopapular rash involving trunk, extremities, palms and soles of feet
      • 10% develop concurrent wart-like lesions on mucous membranes (condyloma latum) laden with bacteria
    • Latent: asymptomatic but with serologic evidence of infection
    • Tertiary (3 - 15 years postinfection): gummas (benign granulomatous tumors) affecting skin, bone and liver, neurologic, ocular and cardiac complications (e.g., syphilitic aortitis) (BMJ Open 2019;9:e025995)

Diagnosis
  • Tissue biopsy or resection of mass-like lesions
  • Demonstration of T. pallidum spirochetes in tissue by immunohistochemistry
  • Routine stain for organisms are can be negative in patients with sexually transmitted infectious proctitis (including immunostains); therefore, correlation with serologies (syphilis) and rectal swab samples (for lymphogranuloma venereum) is required

Laboratory
  • Nontreponemal assays (serum) (J Clin Microbiol 2021;59:e0010021, MMWR Recomm Rep 2024;73:1)
    • Venereal disease research laboratory (VDRL), rapid plasma reagin (RPR)
      • Sensitivity depends upon disease stage (higher in secondary syphilis)
  • Treponemal assays (serum): detect antibodies to T. pallidum
    • Fluorescent treponemal antibody test with absorption (FTA ABS)

Radiology description
  • Computed tomography (CT) typically shows diffuse thickening of the rectum

Radiology images

Images hosted on other servers:
Radiation proctitis

Radiation proctitis

CMV proctitis

CMV proctitis

Axial diffusion weighted imaging

Axial diffusion weighted imaging

Mpox proctitis

Mpox proctitis



Prognostic factors

Case reports

Treatment
  • Primary or secondary stages (including syphilitic colitis)
  • No evidence of penicillin resistance
  • Neurosyphilis
    • Intravenous penicillin G for at least 10 days
  • Jarisch-Herxheimer reaction due to cytokine storm is a potential side effect (Travel Med Infect Dis 2013;11:231)
    • Occurs within 1 hour of treatment
    • Fever, muscle pain, headache, tachycardia

Clinical images

Images hosted on other servers:
Rectal chancres located on posterior wall of rectum and regression

Rectal chancres
located on posterior
wall of rectum
and regression



Microscopic (histologic) description

Microscopic (histologic) images

Contributed by Gillian L. Hale, M.D., M.P.H.
Prominent lymphoid aggregates   Prominent lymphoid aggregates

Prominent lymphoid aggregates

Preserved crypt architecture

Preserved crypt architecture

Ulceration and granulation tissue

Ulceration and granulation tissue


Extensive staining by <i>T. pallidum</i> IHC

Extensive staining by T. pallidum IHC

T. pallidum IHC

T. pallidum IHC

T. pallidum immunostain on rectal ulcer

T. pallidum immunostain on rectal ulcer



Positive stains

Negative stains

Electron microscopy description
  • Structural features (Br J Vener Dis 1971;47:315)
    • Sheath, superficial and deep bundles of fibrins, nuclear vacuole, mesosomes, ribosomes
  • Reproduction by transverse fission
  • Chancres show intracellular and extracellular treponemes
  • Prolonged presence of treponemes in plasma cells may explain persistent serological reactions


Electron microscopy images

Images hosted on other servers:
T. pallidum spirochete

T. pallidum spirochete



Sample pathology report
  • Rectum, biopsy:
    • Syphilitic proctitis (see comment)
    • Comment: Sections of the rectum show prominent lymphohistiocytic and plasmacytic inflammation with lymphoid aggregates, minimal to mild crypt architectural distortion and mild focal active (neutrophilic) inflammation. No viropathic inclusions are identified. A T. pallidum immunohistochemical stain was performed and evaluated and highlights numerous spirochetes. The overall features are those of syphilitic proctitis.

Differential diagnosis
Lymphogranuloma venereum
Definition / general
  • Sexually transmitted infection caused by invasive serovars of Chlamydia trachomatis (serovars L1, L2, L3)

Essential features
  • Mucosal involvement by lymphohistiocytic inflammation with prominent plasma cells
  • Histologic features overlap with other sexually transmitted infections (e.g., syphilitic proctocolitis)
  • Requires ancillary clinical testing (e.g., nucleic acid probe from rectal swab or culture sample)

Terminology

ICD coding
  • ICD-10: A56.3 - chlamydial infection of anus and rectum
  • ICD-11: H00348 - lymphogranuloma venereum

Epidemiology
  • Men who have sex with men (Sex Transm Dis 2007;34:783)
  • HIV infection
  • Prevalent in tropical and subtropical regions
  • Rare in the United States

Sites
  • Colon
  • Rectum

Pathophysiology
  • Dissemination from primary site of infection to draining regional lymph nodes
  • HIV may facilitate coinfection by chlamydia through inhibition of mucosal immunity (Gut 2007;56:1476)

Etiology
  • Chlamydia trachomatis, serovars L1, L2 or L3
  • Gram negative obligate intracellular bacteria

Clinical features
  • Genital ulcer or papule with inguinal or femoral lymphadenopathy (Clin Infect Dis 2015;61:S865, Panminerva Med 2014;56:73)
  • Groove sign: swollen, matted lymph nodes that extend along the inguinal ligament
  • Painful defecation
  • Tenesmus
  • Rectal bleeding
  • Primary stage (~3 - 12 days after exposure)
    • Painless genital ulcer or papules (1 - 6 mm)
    • Sores in mouth after oral transmission
  • Secondary stage
    • Tender inguinal or femoral lymphadenopathy (buboes), typically unilateral
    • Oral infection results in cervical lymphadenopathy
    • Anorectal syndrome
  • Late sequelae
    • Lymphatic obstruction
    • Anorectal strictures, fistulae

Diagnosis
  • Endoscopic biopsy can rule out other etiologies (e.g., malignancy, viral infection)
  • Histopathologic features overlap with other bacterial infections (e.g., syphilis) and inflammatory bowel disease
  • Ancillary clinical and laboratory testing is required
  • Reference: Infect Drug Resist 2015;8:39

Laboratory
  • Nucleic acid amplification tests (NAATs) performed on rectal swabs or anogenital lesions

Prognostic factors

Case reports

Treatment

Microscopic (histologic) description
  • Rectal inflammation and ulcer
  • Neuromatous hyperplasia (submucosal, myenteric plexuses)
  • Thickening and fibrosis of bowel wall

Microscopic (histologic) images

Contributed by Lysandra Voltaggio, M.D. and Kevin M. Waters, M.D., Ph.D.
Lymphohistiocytic inflammation, plasma cells

Lymphohistiocytic
inflammation,
plasma cells

Prominent plasma cells

Prominent plasma cells

Prominent plasma cells, cryptitis

Prominent plasma cells, cryptitis



Positive stains

Sample pathology report
  • Rectum, ulcer, biopsy:
    • Focal active colitis with ulcer, prominent lymphohistiocytic inflammation and plasma cells (see comment)
    • Comment: Sections of the rectal ulcer display prominent lymphohistiocytic and plasmacytic inflammation with minimal crypt architectural distortion. The morphologic features are not specific for etiology but the differential diagnosis includes infection, including sexually transmitted infections such as syphilis and lymphogranuloma venerum (which can occur concomitantly), medications and, as a diagnosis of exclusion, inflammatory bowel disease.

Differential diagnosis
Gonorrhea
Definition / general
  • Gonorrheal colitis: Neisseria gonorrhoeae infection involving the colon

Essential features
  • Rare complication of Neisseria gonorrhoeae infection
  • Risk factors include HIV infection, multiple sex partners and men who have sex with men
  • Morphologic features overlap with other infections, inflammatory bowel disease and ischemia
  • Ancillary clinical testing is required and NAAT is the recommended test for rectal specimens

ICD coding
  • ICD-10: A54.6 - gonococcal infection of anus and rectum
  • ICD-11: 1A72.1 - gonococcal infection of rectum

Epidemiology

Sites
  • Colon

Pathophysiology
  • Transmucosal spread of infected genital fluid by direct contact

Etiology
  • Neisseria gonorrhoeae

Clinical features
  • Proctalgia
  • Pruritis
  • Constipation
  • Mucopurulent or bloody discharge
  • Tenesmus
  • Abdominal pain
  • Fever
  • Frequent coinfection with other sexually transmitted infections such as HIV, syphilis, chlamydia (Sex Transm Dis 2020;47:361)
  • Ulceration is less common compared with LGV and syphilis (Ann Gastroenterol 2023;36:275)

Diagnosis
  • NAAT
  • Gram stain has limited sensitivity (< 40%) in rectal specimens
  • Methylene blue stain may be an alternative to Gram stain (Nat Rev Dis Primers 2019;5:79)
  • Endoscopy provides nonspecific findings but facilitates specimen acquisition

Laboratory
  • Culture positive for Neisseria gonorrhoeae
    • Gram negative diplococcus

Prognostic factors
  • Curable with antibiotics
  • Treatment delays due to overlap with inflammatory bowel disease lead to severe proctitis (Int J Infect Dis 2018;75:34)
  • Increasing prevalence of antibiotic resistance, cultures need to be obtained if suspected / confirmed treatment failure (Clin Colon Rectal Surg 2015;28:70)
  • Untreated infections can disseminate to blood and joints

Case reports

Treatment

Microscopic (histologic) description
  • Mild findings compared to other types of infectious proctitis (Am J Clin Pathol 2022;158:559)
    • Mild acute inflammation
    • Scattered lymphoid aggregates
    • Mucosal ulceration

Microscopic (histologic) images

Contributed by Kevin M. Waters, M.D., Ph.D.
Increased chronic inflammation

Increased chronic inflammation

Scattered neutrophils

Scattered neutrophils



Positive stains

Molecular / cytogenetics description
  • NAAT positive for Neisseria gonorrhoeae

Sample pathology report
  • Rectum, biopsy:
    • Mild active proctitis (see comment).
    • Comment: Sections of rectum show mild acute inflammation without features of chronicity. The differential diagnosis includes infection, ischemia and medication effect. Given that NAAT is positive for Neisseria gonorrhoeae, these findings are consistent with gonococcal proctitis.

Differential diagnosis
Herpes simplex virus
Definition / general
  • HSV colitis: rare complication of herpes simplex viruses 1 and 2 (HSV1 / HSV2)

Essential features
  • Rare complication of HSV1 / HSV2 infection involving the colon and rectum
  • Predominantly occurs in immunosuppressed patients
  • Mucosal biopsies show ulceration, characteristic viropathic inclusions and positive HSV1 / HSV2 immunohistochemistry
  • Treatable but poor prognosis with diagnostic delays and immunosuppressive therapy

ICD coding
  • ICD-10: B00.9 - herpesviral infection, unspecified
  • ICD-11: 1F00.Z - herpes simplex infections, unspecified

Epidemiology
  • Rare complication of HSV infection (J Surg Case Rep 2023;2023:rjad225)
  • Men who have sex with men
  • Immunosuppressed patients
    • HIV / AIDS
    • Inflammatory bowel disease on immunosuppressive therapy

Sites
  • Colon
  • Rectum

Pathophysiology
  • Acquired via abraded skin or mucosal surface
  • Immunosuppression facilitates HSV infection or reactivation and can lead to disseminated disease
  • Gastrointestinal involvement usually involves esophagus, perineum or rectum
  • Colon is rarely involved (Cureus 2023;15:e51409)

Etiology
  • Both HSV1 and HSV2 may infect the gastrointestinal tract
  • HSV2 tends to be more prevalent in HSV colitis

Clinical features
  • Hematochezia
  • Diarrhea (watery or bloody)
  • Abdominal pain
  • Fever
  • Nausea
  • Vomiting
  • Fatigue
  • Decreased appetite
  • Urinary urgency
  • Classic herpetic lesions (oral, genital, anal)
  • Tends to present with disseminated HSV (skin, liver)
  • May be complicated by bowel perforation (J Surg Case Rep 2023;2023:rjad225)
  • Endoscopic findings: ulcers, necrotic mucosa (Cureus 2023;15:e51409)

Diagnosis

Laboratory
  • HSV culture (Infect Dis Rep 2021;13:518)
  • HSV nucleic acid testing; high viral load may suggest systemic infection
  • Serology: HSV1 / HSV2 IgG and IgM are of low clinical value due to the high prevalence of seropositivity in the general population and the high potential for false positive results (Am Fam Physician 2005;72:1527)

Radiology description

Radiology images

Images hosted on other servers:
Colonic wall thickening and stranding

Colonic wall thickening and stranding



Prognostic factors
  • Worse prognosis if the diagnosis of infection is delayed and the patient is treated with steroids
  • Worse prognosis in cases of transmural necrosis and perforation

Case reports

Treatment
  • Antivirals (acyclovir, valacyclovir, famcyclovir)
  • In most cases, immunosuppressive agents are thought to exacerbate infection and should be discontinued if an infectious colitis is diagnosed
  • In cases of a concurrent flare of inflammatory bowel disease, immediate antiviral therapy may be futile until the flare is controlled, since inflammation is known to trigger cytomegalovirus (CMV) and HSV reactivation (Cureus 2023;15:e45166)

Clinical images

Images hosted on other servers:
Sigmoidoscopy showing ulcers and necrosis

Sigmoidoscopy showing ulcers and necrosis



Gross description

Gross images

Images hosted on other servers:
Diffuse necrotizing colitis

Diffuse necrotizing colitis



Microscopic (histologic) description
  • Deep ulcers and necrosis, mimicking inflammatory bowel disease (Int J Infect Dis 2018;75:34)
  • Epithelial and stromal cells with classic viropathic changes
    • Cowdry type A intranuclear inclusion
    • Nuclear multinucleation, margination of peripheral chromatin, nuclear molding (3 Ms)


Microscopic (histologic) images

Contributed by Gillian L. Hale, M.D., M.P.H.
Mucosal ulceration

Mucosal ulceration

Viropathic inclusions and ulcer

Viropathic inclusions and ulcer

Viropathic inclusions

Viropathic inclusions

Infected ganglion cells

Infected ganglion cells

HSV1 / HSV2 immunostain

HSV1 / HSV2 immunostain



Positive stains

Negative stains

Electron microscopy description
  • Cells containing marginalized chromatin and numerous viral particles

Electron microscopy images

Images hosted on other servers:

Infected cell with
viral particles
and marginalized
chromatin



Molecular / cytogenetics description
  • PCR of affected tissue (best method for diagnosis)
  • Serum PCR

Sample pathology report
  • Colon, random, biopsy:
    • Active colitis with ulcers, necrosis and abundant herpes simplex virus (HSV1 / HSV2) inclusions (confirmed by immunohistochemistry)

Differential diagnosis
  • Inflammatory bowel disease:
    • Associated with other clinical manifestations (arthralgia, uveitis, episcleritis, aphthous ulcers)
    • Workup negative for infection (histology, PCR, viral culture)
  • Other acute infections:
    • Supportive history (travel history, exposure to sick contacts)
    • Laboratory testing (stool antigen assay, stool ova and parasites, stool PCR, serum PCR, culture)
Board review style question #1
 


A 45 year old man presents with fever, nausea and bloody diarrhea. Colonoscopy is performed and reveals a rectal ulcer, which is biopsied. Which of the following is true regarding the infectious etiology of rectal ulceration in this patient?

  1. Granulomatous inflammation can be observed in ~20% of cases
  2. Infection is highly resistant to penicillin
  3. Infection precludes the need for further infectious disease testing
  4. Organism can readily be identified on silver special stains
Board review style answer #1
A. Granulomatous inflammation can be observed in ~20% of cases. Granuloma occurs in 22% of cases (Open Forum Infect Dis 2021;8:ofab157). Answer D is incorrect because silver stains are insensitive in the diagnosis of T. pallidum. Answer C is incorrect because syphilis often occurs with other infections (e.g., human immunodeficiency virus [HIV], lymphogranuloma venereum, gonorrhea). Answer B is incorrect because syphilis remains highly susceptible to penicillin.

Comment Here

Reference: Sexually transmitted infectious colitis / proctitis
Board review style question #2
A 50 year old man with a history of receptive anal intercourse presents with months of crampy lower abdominal pain and occasional blood in the stool. Colonoscopy is performed and shows left sided nodularity and focal ulceration, concerning for inflammatory bowel disease. Which of the following features would be of value in differentiating syphilitic proctocolitis from inflammatory bowel disease?

  1. Basal lymphocytosis
  2. Florid lymphohistiocytic inflammation
  3. Marked crypt architectural distortion
  4. Prominent mucosal eosinophils
  5. Ulceration
Board review style answer #2
D. Prominent mucosal eosinophils are often seen in inflammatory bowel disease and are not prominent features of syphilitic proctocolitis. Answers A, B, C and E are incorrect because they are features seen in both inflammatory bowel disease and infectious proctitis.

Comment Here

Reference: Sexually transmitted infectious colitis / proctitis
Board review style question #3


Which of the following statements about lymphogranuloma venereum (LGV) colitis is true?

  1. Diagnosis can be distinguished from syphilitic colitis with an immunostain
  2. Diagnosis requires ancillary clinically testing, preferably a rectal swab specimen
  3. Prominent plasma cells differentiate syphilitic colitis from LGV colitis
  4. Silver stains can detect the intracellular bacteria
Board review style answer #3
B. Diagnosis requires ancillary clinically testing, preferably a rectal swab specimen. The diagnosis of LGV colitis cannot be made by histopathology alone but requires additional clinical testing, which is preferably a rectal swab specimen. Answer A is incorrect because there are no commercially available immunostains for LGV colitis. Answer D is incorrect because the intracellular bacteria of Chlamydia trachomatis cannot be diagnosed by silver stain in mucosal biopsies. Answer C is incorrect because syphilis and LGV colitis are both associated with prominent plasma cells.

Comment Here

Reference: Sexually transmitted infectious colitis / proctitis
Board review style question #4


A 31 year old man who has sex with men presents with proctitis. A rectal swab is obtained and sent for PCR and culture. He also receives antibiotics. Ceftriaxone treats the organism that has which of the following microscopic appearances?

  1. Acid fast organisms within foamy histiocytes
  2. Coiled spirochetes
  3. Cytoplasmic inclusion bodies on Giemsa stain
  4. Gram negative diplococci
Board review style answer #4
D. Gram negative diplococci. Ceftriaxone is used to treat Neisseria gonorrhoeae, which appears microscopically as Gram negative diplococci. Answer C is incorrect because cytoplasmic inclusion bodies on Giemsa stain describe Chlamydia trachomatis, which is usually treated with azithromycin. Answer B is incorrect because coiled spirochetes describe Treponema pallidum, which is usually treated with penicillin. Answer A is incorrect because acid fast organisms describe mycobacteria, which are not usually treated with cephalosporins.

Comment Here

Reference: Sexually transmitted infectious colitis / proctitis
Board review style question #5


A 29 year old woman presents with proctitis. A specimen is collected and shows the histologic appearance above. Which of the following is true about the causative organism?

  1. Anorectal infection by this organism most often presents asymptomatically
  2. Gram stain is the most sensitive test for this organism
  3. This organism is an obligate intracellular bacteria
  4. Use of pre-exposure prophylaxis (PrEP) for human immunodeficiency virus (HIV) is associated with a lower risk of infection by this organism
Board review style answer #5
A. Anorectal infection by this organism most often presents asymptomatically. The figure shows Gram negative diplococci, consistent with infection by Neisseria gonorrhoeae. This organism tends to cause symptoms when it infects the urethra but tends to be asymptomatic when infection the pharynx or rectum. Answer B is incorrect because Gram stain has limited sensitivity (< 40%) for Neisseria in rectal specimens; rather, the test of choice is nucleic acid amplification testing (NAAT). Answer D is incorrect because PrEP is associated with a greater risk of gonorrhea, perhaps due to an increase in risky sexual behavior in this population. Answer C is incorrect because Neisseria is a facultative intracellular organism.

Comment Here

Reference: Sexually transmitted infectious colitis / proctitis
Board review style question #6


A 50 year old woman on immunosuppressive therapy for systemic lupus erythematosus presents with abdominal pain and a disseminated vesicular rash around her labia majora and perianal areas. Colonoscopy shows multiple areas of ulcerated and necrotic mucosa. A biopsy is taken from one of these areas with histologic findings shown. Based on the histopathologic findings, what is the most likely causative organism?

  1. CMV
  2. EBV
  3. HSV1 / HSV2
  4. RSV
Board review style answer #6
C. HSV1 / HSV2. The image shows colonic mucosa with characteristic HSV inclusions (multinucleation, margination, molding). Answer A is incorrect because, although CMV is a more common cause of colitis, the features show the molding, multinucleation and peripheral margination of chromatin more typical of HSV. Answers B and D are incorrect because they are not common causes of colitis and would not display the characteristic inclusions shown in the image.

Comment Here

Reference: Sexually transmitted infectious colitis / proctitis
Board review style question #7


A 45 year man with a history of receptive anal intercourse presents with hematochezia. Colonoscopy shows multiple areas of ulcerated and necrotic mucosa. A biopsy is taken from one of these areas with histologic findings shown. Which of the following is the best treatment for this patient?

  1. Abacavir
  2. Acyclovir
  3. Levofloxacin
  4. Methylprednisone
Board review style answer #7
B. Acyclovir. The image shows colonic mucosa with characteristic HSV inclusions (multinucleation, margination, molding). The treatment of choice for HSV is acyclovir. Answer D is incorrect because methylprednisone is used to treat a flare in inflammatory bowel disease and may exacerbate an infectious colitis. Answer A is incorrect because abacavir is used to treat human immunodeficiency virus (HIV). Answer C is incorrect because levofloxacin is used to treat bacterial infections.

Comment Here

Reference: Sexually transmitted infectious colitis / proctitis
Back to top
Home > Colon > Sexually transmitted infectious colitis / proctitis
Image 01 Image 02