Differential Diagnosis for Male External Urethritis
Single Most Likely Diagnosis
- Gonococcal urethritis: This is the most common cause of urethritis in men, especially in those who are sexually active. It is caused by the bacterium Neisseria gonorrhoeae and typically presents with symptoms such as dysuria, urethral discharge, and sometimes urethral itching or redness.
Other Likely Diagnoses
- Chlamydial urethritis: Caused by Chlamydia trachomatis, this is another common sexually transmitted infection that can lead to urethritis. Symptoms may be similar to gonococcal urethritis but are often milder.
- Non-gonococcal, non-chlamydial urethritis: This category includes urethritis caused by other pathogens such as Mycoplasma genitalium, Ureaplasma urealyticum, and Trichomonas vaginalis. The symptoms can vary but often include dysuria and urethral discharge.
- Herpes simplex virus (HSV) infection: Although more commonly associated with genital ulcers, HSV can cause urethritis, especially in the context of an outbreak.
Do Not Miss Diagnoses
- Syphilis: Caused by Treponema pallidum, syphilis can present in its primary stage with a chancre, which can occasionally cause urethral symptoms. Missing this diagnosis can lead to serious complications if left untreated.
- Urethral stricture or obstruction: Conditions that physically obstruct the urethra can cause symptoms mimicking urethritis, such as difficulty urinating or weak urine stream. These conditions require prompt medical attention to prevent complications.
Rare Diagnoses
- Urethral cancer: Although extremely rare, cancer of the urethra can present with symptoms similar to urethritis, such as dysuria, hematuria, or a palpable mass.
- Reiter's syndrome (Reactive Arthritis): A form of reactive arthritis that can occur after certain bacterial infections, including Chlamydia and Gonorrhea, and is characterized by the triad of arthritis, conjunctivitis, and urethritis.
- Behçet's disease: A rare condition that can cause inflammation throughout the body, including the urethra, leading to symptoms of urethritis among other systemic manifestations.