Differential Diagnosis for Testicular Pain

The patient presents with testicular pain, low-grade fever, and a history of pain that began in the tailbone, moved to rectal pain, and radiated to the testicular area. Considering the symptoms and the progression of pain, the following differential diagnoses are possible:

• Single Most Likely Diagnosis

  • Epididymitis: This condition, which is an inflammation of the epididymis (a tube at the back of the testicle that stores and carries sperm), can cause testicular pain, fever, and pain that may radiate from the lower back or rectal area. The patient's symptoms of testicular pain and low-grade fever, along with the progression of pain, align with epididymitis, especially given the lack of reported trauma.

• Other Likely Diagnoses

  • Prostatitis: Inflammation of the prostate gland can cause pain in the rectal area, lower back, and testicles. The patient's symptoms of rectal pain radiating to the testicles could be consistent with prostatitis.
  • Urinary Tract Infection (UTI): While more common in women, men can also develop UTIs, which can cause pain in the lower abdomen, rectal area, and testicles, along with fever.
  • Testicular Torsion: Although the patient denies any injury, testicular torsion is a condition where the spermatic cord becomes twisted, cutting off the blood supply to the testicle. It's a medical emergency that can cause severe testicular pain and might not always be preceded by trauma.

• Do Not Miss Diagnoses

  • Appendicitis: Although the pain of appendicitis typically starts near the belly button and then moves to the lower right abdomen, atypical presentations can occur, especially if the appendix is located in a retrocecal position, potentially causing pain to be referred to the testicles or rectal area.
  • Kidney Stone: A stone moving down the ureter can cause severe pain (renal colic) that might radiate to the groin or testicles, accompanied by fever if there's an associated infection.
  • Testicular Torsion (reiterated for emphasis): Given its potential for severe and irreversible damage if not promptly treated, testicular torsion must be considered, even with the patient's denial of injury.

• Rare Diagnoses

  • Mumps Orchitis: A viral infection that can cause inflammation of the testicles, leading to pain and swelling. It's less common due to vaccination but should be considered, especially if the patient is not vaccinated against mumps.
  • Henoch-Schönlein Purpura (HSP): A form of vasculitis that can cause testicular pain among other symptoms like purpura, abdominal pain, and arthritis. It's rare and more commonly seen in children but can occur in adults.