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.

🔹 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.

🔹 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.

🔹 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).

🔹 Investigations

1. Laboratory Tests

Test	Purpose / Expected Finding
CBC	Leukocytosis (bacterial cause) or normal/lymphocytic (viral).
CRP / ESR	Elevated in bacterial infection.
Serology for Mumps IgM/IgG	Confirms viral etiology (Mumps orchitis).
Urinalysis and Urine Culture	Identify concurrent UTI pathogens.
NAAT (PCR)	Detect Chlamydia and Gonorrhea in younger males.
HIV & STI screening	If sexual transmission suspected.

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).

🔹 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.

🔹 Complications

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

🔹 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.

🔹 Summary Table

Feature	Viral Orchitis	Bacterial Orchitis (Epididymo-Orchitis)
Onset	Sudden, post-mumps	Gradual, secondary to epididymitis
Systemic symptoms	Fever, malaise, parotitis	Dysuria, urinary frequency
Ultrasound	Hyperemia, enlarged testis	Hyperemia in both epididymis & testis
Definitive treatment	Supportive only	Antibiotics (Ceftriaxone + Doxycycline / Levofloxacin)
Complications	Atrophy, infertility	Abscess, infertility
Follow-up	1–2 weeks	3–7 days

🔑 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.