Differential Diagnosis for Testicular Pain and Swelling
Single Most Likely Diagnosis
- Chlamydia trachomatis infection: This is the most likely cause given the patient's age, symptoms of urethritis (dysuria and urethral discharge), and the presence of neutrophils on the gram stain without visible organisms. Chlamydia is a common cause of nongonococcal urethritis and can lead to epididymitis, which presents with testicular pain and swelling.
Other Likely Diagnoses
- Neisseria gonorrhoeae infection: Although the gram stain did not show organisms, gonorrhea is another common cause of urethritis and can cause epididymitis. The symptoms of dysuria, urethral discharge, and testicular pain are consistent with gonococcal infection.
- Epididymitis due to other bacterial causes: Other bacteria, such as Escherichia coli, can cause epididymitis, especially in men who are uncircumcised or have underlying urological conditions. However, the presence of urethral discharge and dysuria suggests a sexually transmitted infection is more likely.
Do Not Miss Diagnoses
- Testicular torsion: Although less likely given the 36-hour history and the presence of urethral symptoms, testicular torsion is a medical emergency that requires immediate attention. It typically presents with sudden, severe testicular pain and can lead to testicular loss if not promptly treated.
- Appendicitis or other abdominal conditions: In some cases, abdominal conditions like appendicitis can refer pain to the testicles. While less common, these conditions can be serious and require prompt diagnosis and treatment.
Rare Diagnoses
- Mumps orchitis: This viral infection can cause testicular pain and swelling, but it is less common in adults and typically associated with parotid gland swelling.
- Tuberculous epididymitis: This is a rare condition in developed countries but can occur in individuals with tuberculosis. It would be considered in patients with risk factors for TB or those who have been diagnosed with TB in the past.
- Spermatic cord torsion or other vascular issues: These are rare conditions that can cause testicular pain due to vascular compromise. They are less likely given the patient's presentation but should be considered in the differential diagnosis.