A male patient with Chlamydia peritonitis: Case report

Background

Pelvic inflammatory disease (PID) is a well-known entity in women. However, on rare occasions, men can present with peritonitis caused by Chlamydia trachomatis as well. It is important to know and recognise this entity in order to avoid unnecessary investigations and commence prompt treatment.

Presentation

We present the case of a 52-year-old man. He had a history of a sigmoidal adenocarcinoma with solitary liver metastasis 20 years earlier, that was curatively treated with colorectal surgery, adjuvant chemotherapy and surgical resection of the liver lesion. After a long heterosexual relationship, the patient came out as gay 3 years ago. Since then, he has been taking event-driven pre-exposure prophylaxis (PrEP) for HIV under the form of emtricitabine/tenofovir and uses no other medication. There was no history of previous sexually transmitted infections (STI); the last routine STI check-up (including rectal PCR for Chlamydia) was 4 months prior to the current presentation.

The patient visited the Emergency Department due to foot pain for the past 2 weeks without improvement under NSAID. An ultrasound showed hydrops and synovial proliferation of one of the foot joints. He was advised rest, ice application and continuation of NSAID. Six days later he was referred to the Emergency Department by his general practitioner because of an elevated C-reactive protein (CRP) of 280 mg/L and fever up to 40°C. Upon further questioning the patient admitted to having nightly fevers for 2 weeks, and also reported night sweats and weight loss. He also experienced a new pain in both abdominal flanks.

Investigations

CT scan of the abdomen showed inflammation of the peritoneal sheets and slight oedema of the ascending colon. He was admitted to the Gastroenterology ward for IV antibiotics, fluids and antipyretics. Blood and urine cultures were taken. He was started on intravenous amoxicillin/clavulanate but despite this treatment, continued developing high fevers and night sweats for two subsequent days and CRP rose to 293 mg/L.

Serology for HIV, syphilis, HAV, HBV, HCV, HEV, CMV and EBV were all negative. All blood and urine cultures remained negative. PCR for Chlamydia trachomatis was positive on a rectal swab; further PCR analysis by the National STI Reference Centre (Institute of Tropical Medicine, Antwerp, Belgium) confirmed the lymphogranuloma venereum (LGV) serovars L1-3. Both urinary sample and throat swab PCR were negative for Chlamydia trachomatis.

Differential diagnosis

Before the CT scan, based on clinical examination, differential diagnoses that were considered were acute appendicitis, colitis and diverticulitis. Given the night sweats, weight loss, high inflammation and risk behaviour, other STIs such as a primary infection with HIV and syphilis were also considered. After the findings on the CT scan one of the concerns was recurrence of malignancy, however the CT scan nor the clinical course were typical, and symptoms very quickly subsided. CEA was normal.

Treatment

Upon PCR positivity for Chlamydia the patient was started on doxycycline (100 mg bid) and discharged from the hospital. Five days later, he was re-evaluated in the outpatient clinic. His fevers and night sweats had subsided and CRP levels dropped to 27 mg/L. The pain in both his abdomen and his foot had disappeared completely. Doxycycline treatment was continued for a total of 3 weeks as first-line treatment for LGV. ¹ Three months after the episode, he is symptom free and has no biochemical signs of inflammation. Although there is no formal proof of intraperitoneal Chlamydia (as no laparoscopy was performed), the history, the clinical course and the response to treatment makes Chlamydia the most probable cause of the peritonitis.

Discussion

Chlamydia trachomatis infection is a well-known and very frequent sexually transmitted disease. Up to 70% of women have an asymptomatic infection. ² In a selection of female patients, the infection migrates upwards through the reproductive tract up to the fallopian tubes, and may cause pelvic inflammatory disease (PID) with potential long-term impact on fertility. ²

In men, the most common manifestation of a symptomatic infection is urethritis. ³ The LGV serovars are known to cause proctitis or proctocolitis, especially in men who have sex with men (MSM). ⁴

Very rarely, a rectal infection can translocate through the bowel wall and cause peritonitis. To the best of our knowledge, only two such cases have been published. One case reported on a MSM patient who developed Fitz-Hugh-Curtis syndrome following a Chlamydia proctitis. ⁵ Another recent publication reports a similar clinical picture of an immunocompetent man with acute abdominal pain and signs of peritonitis on the CT scan. ⁶

Another well-established entity secondary to STI is sexually acquired reactive arthritis (SARA), with Chlamydia being one of the most common causes. ⁷ The reactive arthritis of one of his foot joints was most likely the first manifesting symptom of Chlamydia infection.

Learning points

Chlamydia trachomatis infection is a very common sexually transmitted disease, usually only causing minor symptoms of urethritis in men. However, male patients can develop an infectious peritonitis and reactive arthritis caused by an LGV type Chlamydia trachomatis. In patients with a STI risk profile and unexplained peritonitis, a rectal swab for Chlamydia PCR should be considered.