Anorectal Infections

Key Features

• Proctitis

  • Most cases are sexually transmitted, especially by anal-receptive intercourse

  • Causes include

    • Neisseria gonorrhoeae

    • Treponema pallidum (syphilis)

    • Chlamydia trachomatis, herpes simplex virus type 2 (HSV-2)

    • Human papillomavirus (HPV)

• Venereal warts (condylomata acuminata)

  • Caused by HPV

  • Occur in up to 25% of men who have sex with men

• Proctocolitis

  • Inflammation that extends above the rectum to the sigmoid colon or more proximally

  • Causes include

    • Campylobacter

    • Entamoeba histolytica

    • Shigella

    • Enteroinvasive Escherichia coli

Clinical Findings

• Proctitis

  • Anorectal discomfort

  • Tenesmus

  • Constipation

  • Discharge

• Gonorrhea proctitis

  • Itching

  • Burning

  • Tenesmus

  • Mucopurulent discharge

• Complications of untreated gonorrheal infections

  • Strictures

  • Fissures

  • Fistulas

  • Perirectal abscesses

• Anal syphilis

  • Asymptomatic

  • Chancre

  • Proctitis

• In primary syphilis, chancre may mimic a fissure, fistula, or ulcer; proctitis or inguinal lymphadenopathy may be present

• In secondary syphilis, condylomata lata may be seen, with foul-smelling mucus discharge

• C trachomatis causes proctitis similar to gonorrhea or lymphogranuloma venereum, proctocolitis with fever and bloody diarrhea, painful perianal ulcerations, anorectal strictures and fistulas, and inguinal adenopathy (buboes)

• HSV-2 proctitis

  • Severe pain, itching, constipation, tenesmus, urinary retention, and radicular pain

  • Small vesicles or ulcers in the perianal area or anal canal

• Venereal warts are noted on examination of the perianal skin and within the anal canal; otherwise asymptomatic

• Higher rate of HPV progression to high-grade dysplasia or anal cancer in HIV-positive persons

Diagnosis

• Gonorrhea proctitis

  • Rectal swab specimens should be taken during anoscopy for culture

  • Gram staining is unreliable

  • Cultures should also be taken from the urethra and pharynx in men and from the cervix in women

• Anal syphilis

  • Dark-field microscopy or fluorescent antibody testing of scrapings from the chancre or condylomata

  • Serum VDRL positive in 75% of primary and 99% of secondary syphilis

• Diagnosis of chlamydial infection is established by serology, culture, or PCR-based testing of rectal discharge or rectal biopsy

• HSV-2

  • Sigmoidoscopy shows vesicular or ulcerative lesions in the distal rectum

  • Diagnosis by viral culture, polymerase chain reaction, or antigen detection assays of vesicular fluid

Treatment

• See treatment of specific infections

• Examine and treat patient's sexual partners

• Surveillance anoscopy every 3–6 months in HIV-positive persons