Urethritis

Definition/diagnostic criteria

Urethritis is an inflammation of the urethra, primarily caused by bacterial or viral infections. The British Association for Sexual Health and HIV (BASHH) distinguishes between gonococcal urethritis (GU) and non-gonococcal urethritis (NGU) based on the causative organism. Diagnostic criteria include the presence of urethral discharge, dysuria, or a history of sexual exposure to infection. Microscopic examination of urethral swabs demonstrating ≥5 polymorphonuclear leucocytes (PMNL) per high power field (HPF) supports the diagnosis.

Epidemiology

Urethritis is a common condition in the UK, particularly among sexually active young adults. NGU is more prevalent than GU, with Chlamydia trachomatis being the most common identifiable cause of NGU. Mycoplasma genitalium and Trichomonas vaginalis are also notable pathogens. The incidence of urethritis has been rising, attributed to increased detection and reporting, along with real increases in infections due to changing sexual behaviours.

Diagnosis

Clinical features

Patients with urethritis may be asymptomatic (particularly females), or may present with urethral discharge, dysuria, pruritus. The discharge may vary in colour and consistency. It is essential to consider the patient’s sexual history, including the number of partners and condom use, to assess risk for sexually transmitted infections (STIs).

Investigations

Investigations include nucleic acid amplification tests (NAATs) for C. trachomatis and N. gonorrhoeae from first-void urine samples or urethral swabs. Additional tests for M. genitalium, herpes simplex virus, and T. vaginalis may be considered based on clinical suspicion and patient history. Typical abnormalities include the presence of PMNLs on microscopy of urethral smears and positive NAATs for specific pathogens.

Treatment

Ideally, these cases should be referred to STI clinics for testing, contact tracing, and treatment. If, for whatever reason, this is not feasible, then, for NGU in men, doxycycline 100 mg twice daily for 7 days is recommended as first-line treatment, with azithromycin 1 g as a single dose as an alternative, particularly when compliance is a concern. For GU, ceftriaxone 500 mg intramuscularly as a single dose, or ciprofloxacin 500mg orally as a single dose, is recommended. Partners should be notified, tested, and treated if necessary.

Prognosis

With appropriate treatment, the prognosis for urethritis is generally good. However, complications can occur, including epididymitis, prostatitis, and pelvic inflammatory disease in females. Recurrence is possible, especially in cases of NGU, underscoring the importance of partner notification and treatment. Long-term complications from untreated urethritis can include infertility and chronic pain.