Orchitis Overview: Viral vs Bacterial Causes, Diagnosis, and Treatment Strategies

🔹 Definition

Orchitis is an inflammation of the testicular parenchyma.It can occur as:

• Primary orchitis (rare, often viral—classically mumps), or
• Secondary orchitis (extension from epididymitis, known as epididymo-orchitis).

It most commonly affects post-pubertal males and presents with acute testicular pain and swelling.

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🔹 Etiology

1. Viral Causes (most common)

• Mumps virus → classic cause in post-pubertal males.
  • Occurs in up to 30% of men with mumps.
  • Typically develops 4–7 days after parotitis.
• Other viruses: Coxsackie, Rubella, Echovirus, Varicella.

2. Bacterial Causes

• Usually secondary to epididymitis due to ascending infection.
  • E. coli, Pseudomonas, Staphylococcus, and Klebsiella.
• Sexually transmitted pathogens in younger men: Chlamydia trachomatis, Neisseria gonorrhoeae.

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🔹 Pathophysiology

• In viral orchitis, direct viral invasion triggers inflammatory infiltration and edema of seminiferous tubules → testicular pain, swelling, and potential atrophy due to pressure-induced ischemia.
• In bacterial orchitis, infection ascends through the vas deferens → epididymal extension → testicular involvement.

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🔹 Diagnostic Criteria

Clinical Diagnosis

• Sudden onset of unilateral or bilateral testicular pain and swelling.
• Fever and malaise (often precedes pain in mumps).
• Testis: tender, swollen, and erythematous; epididymis may also be inflamed.
• No relief of pain with scrotal elevation (Prehn’s sign negative).
• Cremasteric reflex preserved (unlike torsion).
• May follow recent parotitis (mumps).

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🔹 Investigations

1. Laboratory Tests

2. Imaging

Scrotal Ultrasound with Color Doppler

• Confirms diagnosis and rules out torsion.
• Findings:
  • Enlarged, heterogeneous testis with increased vascularity (hyperemia) in orchitis.
  • Possible hydrocele or scrotal wall thickening.
  • Absence of blood flow → indicates testicular torsion (surgical emergency).

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🔹 Management Determine Setting

• Outpatient (OPD): mild, viral, or stable bacterial cases.
• Inpatient (IPD): severe pain, abscess, systemic illness, or diagnostic uncertainty.

A. Viral Orchitis (e.g., Mumps Orchitis)

🩹 Definitive Treatment:

• No specific antiviral therapy; treatment is supportive.
• Steroids and antivirals are not recommended (no proven benefit).

💊 Supportive Care:

• Bed rest until afebrile and pain improves.
• Scrotal elevation and support (e.g., folded towel).
• NSAIDs or analgesics:
  • Ibuprofen 400 mg PO q8h with meals, or Paracetamol 500 mg q6h PRN.
• Cold compresses to reduce swelling.
• Hydration and rest.

⏱️ Follow-up:

• Monitor for resolution of pain and swelling (usually improves within 7–10 days).
• Educate about potential infertility if bilateral involvement.

B. Bacterial Orchitis / Epididymo-Orchitis

🦠 Definitive (Antibiotic) Treatment: Tailor regimen to age and likely pathogen.

1. STI-related (<35 years):

• Ceftriaxone 500 mg IM single dose + Doxycycline 100 mg PO bid × 10 days

2. Non-STI / UTI-related (>35 years):

• Levofloxacin 500 mg PO daily × 10 days OR
• Ofloxacin 300 mg PO bid × 10 days

3. Mixed risk (anal intercourse):

• Ceftriaxone 500 mg IM single dose + Levofloxacin 500 mg PO daily × 10 days

💊 Supportive Treatment (Same as Viral):

• NSAIDs, scrotal support, rest, hydration.

C. Partner Management

• If STI-related: test and treat sexual partners (last 60 days).
• Abstain from sexual activity until completion of treatment and resolution of symptoms.

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🔹 Complications

• Testicular atrophy (common in mumps orchitis).
• Infertility (especially if bilateral).
• Chronic pain or abscess formation.
• Epididymo-orchitis extension.

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🔹 Prognosis

• Viral: usually resolves in 1–2 weeks; atrophy in up to 50% of affected testes.
• Bacterial: full recovery with appropriate antibiotics; early treatment prevents infertility.

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🔹 Summary Table

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🔑 Clinical Pearls

• Always exclude testicular torsion in acute scrotal pain.
• Mumps orchitis usually follows parotitis by several days.
• Steroids & antivirals have no proven benefit in viral orchitis.
• Educate patients about mumps vaccination (MMR) for prevention.