Alexander McMillan1, 2
(1)
Department of Genitourinary Medicine, NHS Lothian, Edinburgh Royal Infirmary, Edinburgh, Uk
(2)
University of Edinburgh, Edinburgh, Uk
Alexander McMillanFormerly, Consultant Physician, part-time Senior Lecturer
Email: a.amcmm@btinternet.com
Abstract
A 20-year-old gay man, Eric, presents to a Sexual Health clinic with a 5-day history of constipation and discomfort in the anal region. He has noticed that his stools have been coated with “slime” tinged with blood. There are no other symptoms, his general health is good, and there is no relevant past history. His most recent sexual contact had been 1 week previously with an unknown British male with whom he had unprotected receptive anal intercourse. He has had no other sexual contacts within the preceding 6 months. Eric first became sexually active at the age of 17 years and he has had about 20 lifetime sexual partners. With the exception of his most recent sexual contact, insertive and receptive anal intercourse has been protected. He had a sexual health screen about 1 year previously when no infection was found. At that time he had been vaccinated against hepatitis A and B, and subsequent serological testing showed that he had a good antibody response to the former vaccine. He has no known drug allergies.
A 20-year-old gay man, Eric, presents to a Sexual Health clinic with a 5-day history of constipation and discomfort in the anal region. He has noticed that his stools have been coated with “slime” tinged with blood. There are no other symptoms, his general health is good, and there is no relevant past history. His most recent sexual contact had been 1 week previously with an unknown British male with whom he had unprotected receptive anal intercourse. He has had no other sexual contacts within the preceding 6 months. Eric first became sexually active at the age of 17 years and he has had about 20 lifetime sexual partners. With the exception of his most recent sexual contact, insertive and receptive anal intercourse has been protected. He had a sexual health screen about 1 year previously when no infection was found. At that time he had been vaccinated against hepatitis A and B, and subsequent serological testing showed that he had a good antibody response to the latter vaccine. He has no known drug allergies.
20.1 What Is the Most Likely Cause of His Symptoms, and What Are Possible Causes?
The history is suggestive of a distal proctitis, Table 20.1 indicating the sexually transmissible causes of this.
Table 20.1.
Sexually transmitted causes of a distal proctitis.
|
Neisseria gonorrhoeae Chlamydia trachomatis: • Genotypes D – K • Genotypes L1, L2, L2a, and L3 Herpes simplex virus Treponema pallidum |
Gonococcal or chlamydial proctitis is the most likely diagnoses in this case. Rectal gonorrhoea is symptomless in at least two-thirds of cases, and infection with the D – K genotypes of Chlamydia trachomatisis symptomless in about 90% of cases. Infection with the lymphogranuloma venereum (LGV) genotypes of C. trachomatis, however, usually causes a severe inflammatory response, often with systemic features. Primary herpetic proctitis is often, but by no means always accompanied by perianal ulceration with considerable pain, low-grade fever, and sometimes urinary hesitancy from sacral nerve irritation. If the sexual history is accurate, primary syphilis of the rectum is unlikely, although proctitis can form part of the clinical picture of secondary infection even in the absence of skin lesions.
Eric looks well and he is not in distress. There is no abdominal tenderness or guarding, and neither liver nor spleen is palpable. The external genitalia appear normal and there is no significant inguinal lymph node enlargement. The perianal region is normal. During anoscopy, the normal vascular pattern of the distal rectal mucosa is absent, 1 and mucopus is noted in the lumen of the rectum. The mucosa appears normal beyond 12 cm from the anal margin.
The findings confirm a diagnosis of distal proctitis.
20.2 What Is Your Immediate Management?
Rectal specimens are taken for the identification of Neisseria gonorrhoeae, C. trachomatis, and herpes simplex virus, as described in Cases 4 and 16. In addition, a Gram-stained smear is prepared for immediate microscopical examination. If Gram-negative diplococci are identified in the smear, a provisional diagnosis of rectal gonorrhoea can be made and specific treatment initiated without delay. The sensitivity of the test on rectal specimens, however, is only between 70 and 80%, and, as other species of Neisseria, particularly N. meningitidis, which are morphologically identical to the gonococcus, are commonly found in the rectum, the specificity of this test may be low.
Microbiological tests for infections at other anatomical sites are also undertaken, and a blood sample is taken for serological testing for syphilis and HIV.
Gram-negative diplococci (see http://Case 7 ) are identified within the cytoplasm of the numerous polymorphonuclear leucocytes noted in the rectal smear.
The presumptive diagnosis is rectal gonorrhoea and treatment is given. The treatment regimens described in http://Case 7 are as efficacious in the treatment of rectal infection as they are in that of genital tract gonorrhoea. As at least one-quarter of men with rectal gonorrhoea have concurrent chlamydial infection, empirical treatment for this should be given simultaneously. Although data on its efficacy in treating chlamydiae in the rectum are scant, azithromycin in a single oral dose of 1 g is the most commonly used drug. Alternatively, doxycycline in an oral dose of 100 mg twice daily for 7 days may be given. Treated patients should be reviewed a week after completion of treatment for reasons discussed in http://Case 7.
Eric is treated with single oral doses of cefixime and azithromycin and is reviewed 1 week later. He is now symptomless, he has had no adverse events from treatment, and he has had no sexual contact in the intervening period. The laboratory tests confirmed the diagnosis of gonorrhoea and C. trachomatis DNA was detected in a rectal specimen. Genotyping showed that the DNA detected was not of the LGV genotype. Other tests, including those for syphilis and HIV were negative. He has been unable to identify and contact the man who was the source of his infection.
Rectal gonorrhoea is an important infection to identify. As stated above, it is often symptomless, but may be complicated by perianal abscess formation, and, rarely, disseminated infection (see http://Case 24). In addition, it is clear that gonorrhoea facilitates the transmission of HIV infection.
Counseling on risk reduction for the acquisition of sexually transmitted infections, including HIV, should be undertaken routinely. In this case, serological tests for syphilis should be repeated 3 months after the sexual risk, the pre-patent period of syphilis being between 10 and 90 days. Similarly, repeat HIV testing is also indicated at that time, or earlier if indicated.2
Footnotes
1
Although absence of the normal vascular pattern of the mucosa is a feature of proctitis, visible vasculature is commonly absent in the distal 10 cm of the normal rectum.
2
Earlier testing may be indicated if the person is a known contact of an HIV-infected individual, or if he/she develops clinical features suggestive of primary HIV infection.