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)

• Condylomata acuminata (warts)

  • 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

  • Mucus or bloody discharge

• Gonorrhea proctitis

  • Itching

  • Burning

  • Tenesmus

  • Mucopurulent discharge

• Complications of untreated gonorrheal infections

  • Strictures

  • Fissures

  • Fistulas

  • Perirectal abscesses

• Anal syphilis

  • Asymptomatic, or perianal pain and discharge

  • Chancre

  • Proctitis

  • Inguinal lymphadenopathy may be present

• In primary syphilis, chancre may mimic a fissure, fistula, or ulcer

• In secondary syphilis, condylomata lata (pale brown, flat verrucous lesions) may be seen, with foul-smelling mucus discharge

• C trachomatis causes proctitis similar to gonorrheal proctitis or lymphogranuloma venereum characterized by

  • Proctocolitis with fever and bloody diarrhea

  • Painful perianal ulcerations

  • Anorectal strictures and fistulas

  • Inguinal adenopathy (buboes)

• HSV-2 proctitis

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

  • Develops 4–21 days after exposure

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

• Condylomata acuminata are noted on examination of the perianal skin and within the anal canal and present with

  • Itching

  • Bleeding

  • Pain

  • Or may be asymptomatic

• In persons with HIV, higher rates of HPV progression to high-grade dysplasia or anal cancer

DIAGNOSIS

• Gonorrhea proctitis

  • Nucleic acid amplification testing

    • Has excellent sensitivity and specificity

    • Preferred in most clinical settings

  • Rectal swab specimens should be taken during anoscopy

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

  • Culture with sensitivity testing may be required in patients with suspected infection recurrence

• Anal syphilis

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

  • Serum venereal disease research laboratory (VDRL) or rapid plasma regain (RPR) test is positive in 75% of primary and 99% of secondary syphilis

• Diagnosis of chlamydial infection is established by polymerase chain reaction (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, PCR, or antigen detection assays of vesicular fluid

• Condylomata acuminata diagnosed with biopsy from large or suspicious lesions

TREATMENT

• See treatment of specific infections

• Examine and treat patient's sexual partners

• Surveillance anoscopy every 3–6 months in persons with HIV who have

  • Condylomata

  • Detectable serum HIV RNA levels