What infection can cause testicular atrophy in a person who has had unprotected oral sex, potentially leading to conditions such as epididymitis caused by sexually transmitted infections (STIs) like chlamydia or gonorrhea?

Testicular Atrophy from Sexually Transmitted Infections After Unprotected Oral Sex

Direct Answer

Chlamydia trachomatis and Neisseria gonorrhoeae are the primary sexually transmitted infections that can cause testicular atrophy in your situation, transmitted through unprotected oral sex and progressing to epididymitis if left untreated. 1, 2

How These Infections Lead to Testicular Damage

Transmission and Progression

• Both chlamydia and gonorrhea can be transmitted through oral sex, as the oropharynx serves as a reservoir for these pathogens that subsequently infect the urethra. 3, 4
• These infections typically cause urethritis first (often asymptomatic in 68-92% of cases), then ascend to cause epididymitis, which is the pathway to potential testicular complications. 2, 5
• Among men under 35 years of age, C. trachomatis and N. gonorrhoeae are the most common causes of epididymitis, with sexually transmitted epididymitis usually accompanied by urethritis that is frequently asymptomatic. 1, 6

Mechanism of Testicular Atrophy

• Untreated or inadequately treated epididymitis can progress to orchitis (testicular inflammation), which may result in testicular atrophy as a long-term complication. 1, 7
• Chronic inflammation from C. trachomatis can cause persistent epididymitis lasting months, leading to progressive testicular damage, reduced sperm quality, and potential atrophy. 7

Critical Warning Signs Requiring Immediate Evaluation

Symptoms of Epididymitis

• Unilateral testicular pain and tenderness with palpable swelling of the epididymis are the hallmark findings. 1, 5
• Gradual onset of scrotal pain (not sudden) with possible urethral discharge, dysuria, or fever suggests epididymitis rather than testicular torsion. 5
• The affected testis remains in normal anatomic position with intact cremasteric reflex, distinguishing this from torsion. 5

Emergency Differentiation

• Sudden, severe testicular pain requires emergency evaluation for testicular torsion, which is a surgical emergency more common in adolescents. 1, 6

Recommended Diagnostic Approach

Essential Testing

• Obtain urethral Gram stain showing ≥5 polymorphonuclear leukocytes per oil immersion field to diagnose urethritis and presumptively identify gonorrhea. 1, 6
• Perform nucleic acid amplification test (NAAT) or culture for both N. gonorrhoeae and C. trachomatis from urethral swab or first-void urine. 1, 6
• Order syphilis serology and offer HIV counseling/testing, as sexually transmitted epididymitis indicates risk for other STIs. 6, 4

Treatment to Prevent Testicular Atrophy

Standard Empiric Therapy (Under 35 Years)

The CDC recommends immediate empiric treatment before culture results are available to prevent progression and complications: 1, 6

• Ceftriaxone 250 mg intramuscular injection as a single dose 1, 6, 8
• PLUS Doxycycline 100 mg orally twice daily for 10 days 1, 6, 8

Critical Treatment Principles

• Complete the entire 10-day antibiotic course even if symptoms improve earlier, as stopping prematurely leads to treatment failure and chronic complications. 6, 9
• Treatment within 3 days of symptom onset is crucial; failure to improve within 3 days requires reevaluation of diagnosis and therapy. 1, 6
• Persistent swelling and tenderness after completing antimicrobial therapy requires evaluation for testicular cancer, tuberculous epididymitis, or fungal infection. 1, 6

Adjunctive Measures

• Bed rest with scrotal elevation (using rolled towel or supportive underwear) until fever and local inflammation subside. 1, 6, 9
• Analgesics for pain control during the acute phase. 6, 9

Prevention of Reinfection and Partner Management

Sexual Activity Restrictions

• Abstain from all sexual intercourse (including oral sex) until both you and your partner(s) have completed treatment and are symptom-free. 1, 6, 9

Partner Notification

• All sexual partners from the past 30-60 days must be evaluated and treated, even if asymptomatic, as 68-92% of infected men have no symptoms. 1, 6, 2
• Failure to treat sex partners leads to reinfection and continued risk of complications including testicular atrophy. 2, 9

Follow-Up Testing

• Retest 3 months after treatment completion due to high likelihood of reinfection (not to confirm cure). 2

Special Consideration: Lymphogranuloma Venereum (LGV)

Emerging Concern

• C. trachomatis LGV serovars (L1-L3) can cause chronic epididymitis and testicular complications, even in heterosexual HIV-negative men without typical LGV symptoms (inguinal buboes). 7
• LGV-associated chronic epididymitis may require extended treatment with doxycycline 100 mg twice daily for 45 days rather than the standard 10 days. 7
• Consider LGV testing if symptoms persist despite standard therapy or if chronic epididymitis develops. 7

Common Pitfalls to Avoid

• Don't assume you're infection-free because you have no symptoms—most chlamydia and gonorrhea infections in men are asymptomatic but still cause complications. 2
• Don't delay treatment waiting for test results—empiric therapy prevents progression to chronic complications and testicular atrophy. 6, 2
• Don't resume sexual activity when pain improves—the infection requires the full antibiotic course and partner treatment to prevent reinfection. 6, 9
• Don't ignore persistent symptoms after treatment—this may indicate resistant organisms, alternative diagnoses (including malignancy), or LGV requiring extended therapy. 1, 6, 7