Can autoimmune orchitis or mumps orchitis be asymptomatic and cause testicular atrophy in a sexually active adult male with no prior painful episode?

Can Autoimmune or Mumps Orchitis Present Asymptomatically with Testicular Atrophy?

Yes, primary autoimmune orchitis is characteristically asymptomatic and can cause testicular atrophy in sexually active adult males without any prior painful episode, whereas mumps orchitis typically presents with acute symptoms but can occasionally occur without parotitis or systemic features. 1, 2

Primary Autoimmune Orchitis: The Asymptomatic Culprit

Primary autoimmune orchitis is defined by infertility and asymptomatic orchitis associated with antisperm antibodies (ASA) in 100% of cases, occurring in infertile men without any systemic disease and usually presenting without symptoms. 1

Key Diagnostic Features

• The condition manifests as testicular inflammation with ASA directed to the basement membrane or seminiferous tubules, discovered incidentally during infertility workup rather than through symptomatic presentation 1
• Patients have no history of testicular pain, erythema, or swelling—the diagnosis is made when investigating subfertility or during routine examination 1
• Testicular atrophy develops silently as a consequence of chronic inflammation, blood-testis-barrier disruption, and progressive apoptosis of spermatocytes and spermatids 1

Pathophysiology

• The mechanism involves T cell response with pro-inflammatory cytokine production, leading to altered blood-testis-barrier permeability, ASA production, and germ cell apoptosis—all occurring without overt clinical symptoms 1
• ASA causes immobilization and/or agglutination of spermatozoa, blocking sperm-egg interaction and resulting in infertility as the presenting complaint 1

Mumps Orchitis: Usually Symptomatic but Exceptions Exist

Mumps orchitis typically presents with acute testicular pain and swelling, but can occur without parotitis or systemic features in up to 50% of mumps infections, making diagnosis challenging. 3, 2

Clinical Presentation Spectrum

• Only 30%-40% of mumps infections produce typical acute parotitis; 15%-20% are completely asymptomatic and up to 50% present with nonspecific or primarily respiratory symptoms 3
• Serious complications of mumps, including orchitis, can occur without evidence of parotitis—a critical diagnostic pitfall 3
• A prospective study found mumps epididymo-orchitis in patients presenting with testicular symptoms but no parotid swelling or systemic illness, confirmed by positive IgM serology 2

Orchitis Characteristics

• Orchitis affects up to 38% of postpubertal men with mumps infection 3
• Among 23 patients with epididymo-orchitis symptoms, three had positive mumps IgM serology despite none having parotid swelling, demonstrating that mumps can present solely with genital symptoms 2
• The condition can be unilateral (more common) or bilateral, with bilateral involvement occurring in 16-65% of affected patients 4, 5

Atrophy Risk and Timeline

• Testicular atrophy is a well-documented sequela, with one series reporting atrophy in 7 of 9 affected testes (78% atrophy rate) 5
• The duration between initial mumps orchitis diagnosis and ultrasonographic confirmation of testicular atrophy ranges from 25 to 230 days (mean 95.9 days) 6
• Affected testes become 23%-55% smaller in volume (mean 44.7% reduction) compared to contralateral normal testes 6
• Despite high atrophy rates, sterility is thought to occur only rarely, particularly when unilateral 3

Distinguishing Primary Autoimmune from Secondary Autoimmune Orchitis

Secondary autoimmune orchitis, unlike the primary form, is characterized by symptomatic orchitis and/or testicular vasculitis associated with systemic autoimmune disease, particularly vasculitis, with patients demonstrating testicular pain, erythema, and/or swelling. 1

• ASA are found in up to 50% of secondary autoimmune orchitis cases, especially in systemic lupus erythematosus patients 1
• The presence of systemic autoimmune disease and symptomatic presentation clearly differentiates secondary from primary autoimmune orchitis 1

Diagnostic Approach for Asymptomatic Testicular Atrophy

Clinical Assessment

• Obtain detailed history focusing on: prior mumps exposure or vaccination status, community mumps outbreaks, any episode of testicular discomfort (even mild or transient), fertility concerns, and presence of systemic autoimmune disease 2, 1
• Physical examination findings in primary autoimmune orchitis show testicular atrophy without warmth, erythema, or tenderness 1, 7

Laboratory Evaluation

• For mumps: Obtain mumps IgM and IgG serology, as positive IgM confirms recent infection even in the absence of parotitis 2
• For autoimmune orchitis: Test for antisperm antibodies (ASA), which are present in 100% of primary autoimmune orchitis cases 1
• Exclude sexually transmitted infections (chlamydia PCR, gonorrhea culture) and urinary tract infection (urinalysis, MSSU) 2, 3

Imaging Protocol

• Scrotal ultrasound with Doppler is mandatory to assess testicular volume, echogenicity, and vascularity, and to rule out underlying testicular pathology including malignancy 7, 6
• Ultrasonographic features of post-mumps atrophic testes include: oblong shape (rather than normal elliptical), heterogeneously hypoechoic with multiple hyperechoic islands, decreased vascularity compared to contralateral testis, and 23%-55% volume reduction 6

Critical Clinical Pitfalls

• Never assume mumps orchitis requires parotitis—up to 50% of mumps infections lack typical parotid involvement, and orchitis can be the sole presenting feature 3, 2
• Be aware of community mumps outbreaks when evaluating testicular symptoms, as management and partner notification differ from sexually transmitted epididymo-orchitis 2
• Primary autoimmune orchitis is discovered during infertility evaluation, not through symptomatic presentation—maintain high index of suspicion in subfertile men with testicular atrophy 1
• Inapparent mumps infection may be more common among adults than children, increasing the likelihood of unrecognized orchitis in adult males 3

Management Implications

For Mumps Orchitis

• Systemic treatment with interferon-alpha 2B (3 × 10⁶ IU per day for 7 days) appears highly effective in preventing sterility and testicular atrophy after bilateral mumps orchitis, with acute symptoms resolving within 2-4 days 4
• Systemic immunoglobulin prophylaxis and corticosteroid therapy should be considered given the high atrophy rate (78% in one series) 5
• Application of mumps immunoglobulin in males aged 12-20 years with mumps exposure is recommended as orchitis prophylaxis 5

For Primary Autoimmune Orchitis

• Assisted reproduction is the primary treatment option for infertility related to primary autoimmune orchitis 1
• Immunosuppressive therapy is reserved for secondary autoimmune orchitis associated with systemic disease, though no randomized trials confirm efficacy of any treatment regimen 1