How should unilateral orchitis in a 2‑year‑old boy be evaluated and managed?

Unilateral Orchitis in a 2-Year-Old Male

In a 2-year-old boy presenting with unilateral orchitis, immediately obtain color Doppler ultrasound to rule out testicular torsion (a surgical emergency), then treat presumed epididymo-orchitis with empiric antibiotics while investigating for underlying urinary tract infection and congenital urologic anomalies. 1, 2, 3

Immediate Diagnostic Priorities

Rule Out Testicular Torsion First

• Testicular torsion is a surgical emergency requiring intervention within 6-8 hours and must be excluded before assuming infectious orchitis, as permanent testicular loss occurs without prompt surgical detorsion. 1
• In the 2-year age group, torsion accounts for approximately 31% of acute scrotum presentations, making it equally common as epididymo-orchitis (28%) and torsion of testicular appendages (31%). 4
• Color Doppler ultrasound is mandatory and shows 88-100% sensitivity for distinguishing torsion (absent/decreased flow) from orchitis (increased flow/hyperemia). 5, 2

Key Clinical Distinguishing Features

• Epididymo-orchitis in infants typically presents with fever, scrotal tenderness, and elevated inflammatory markers (leukocytosis, elevated CRP) in 86% of cases, whereas torsion often has normal inflammatory markers. 5
• Absent cremasteric reflex strongly suggests torsion rather than orchitis. 6
• Negative Prehn sign (no pain relief with testicular elevation) indicates torsion, while positive Prehn sign suggests epididymo-orchitis. 1

Ultrasound Findings to Confirm Orchitis

• Hyperemia (increased blood flow) on color Doppler has nearly 100% sensitivity for confirming epididymo-orchitis and definitively excludes torsion. 2
• Enlarged epididymis with increased or decreased echogenicity, scrotal wall thickening, and reactive hydrocele are typical findings. 2
• Up to 20% of epididymitis cases progress to concomitant orchitis, showing increased testicular blood flow. 2

Investigate for Underlying Urinary Tract Pathology

Critical: Epididymo-orchitis in a 2-year-old is strongly associated with urinary tract infection and underlying congenital anomalies.

• Obtain urinalysis and urine culture immediately—all infants with epididymo-orchitis who were tested for UTI had positive results (100% in one series). 5
• In prepubertal boys, enteric organisms (especially E. coli) are the predominant pathogens, not sexually transmitted infections. 2, 7
• Epididymo-orchitis with UTI in infants is a red flag for vesicoureteral reflux (VUR) and other congenital anomalies of the kidney and urinary tract (CAKUT). 3
• After acute treatment, perform voiding cystourethrogram (VCUG) to evaluate for VUR and renal ultrasound to assess for hydronephrosis or structural abnormalities. 3

Empiric Antibiotic Treatment

Start antibiotics immediately after obtaining urine culture, without waiting for inflammatory marker results.

• For a 2-year-old, use antibiotics targeting enteric gram-negative organisms (e.g., ceftriaxone or cephalexin), as this age group does not have sexually transmitted pathogens. 2
• Treatment duration should be 10 days minimum for complicated UTI with epididymo-orchitis. 3
• If the child is febrile or appears ill, initiate intravenous antibiotics; switch to oral once clinically improved (typically 48 hours). 3, 5

Follow-Up and Reassessment

• Re-evaluate at 48-72 hours—lack of clinical improvement mandates reconsideration of alternative diagnoses (abscess, tumor, fungal/mycobacterial infection) and surgical consultation. 2
• Once acute infection resolves, complete urologic workup with VCUG and consider DMSA scan to assess for renal scarring. 3
• If VUR is confirmed, initiate antibiotic prophylaxis and arrange periodic follow-up with pediatric urology. 3

Common Pitfalls to Avoid

• Never assume orchitis without ultrasound confirmation—clinical differentiation between torsion and orchitis is notoriously unreliable, even in experienced hands. 4
• Do not delay surgical exploration if torsion cannot be definitively excluded, as boys requiring orchidectomy for missed torsion present three times later than those with salvageable testes (48 vs. 16.5 hours). 4
• Failure to investigate for underlying urologic anomalies leaves the child at risk for recurrent UTIs and progressive renal damage. 3
• In immunocompromised patients or treatment failures, consider fungal and mycobacterial pathogens that may present with minimal inflammatory response. 2