What are the likely causes and recommended evaluation and treatment for painful scrotal lesions in an adult male?

Painful Scrotal Sores: Diagnosis and Management

Painful scrotal lesions in adult males most commonly represent either infectious causes (particularly herpes simplex virus or bacterial cellulitis) or inflammatory dermatoses (such as lichen sclerosus), and require urgent evaluation to exclude life-threatening necrotizing infections and sexually transmitted diseases.

Immediate Life-Threatening Considerations

Rule out necrotizing soft tissue infection (Fournier's gangrene) first, which presents with rapidly progressive scrotal swelling, intense pain, and potential skin changes including erythema, crepitus, or gangrene. 1

• Beta-hemolytic streptococcal cellulitis can cause rapid fluid accumulation between fascial planes, leading to devascularization and skin gangrene if not immediately decompressed. 1
• Immediate surgical consultation and broad-spectrum antibiotics (penicillin for streptococcal infection) are essential if necrotizing infection is suspected. 1
• Linear incisions for fascial decompression must be performed urgently to prevent irreversible tissue loss. 1

Most Common Infectious Causes

Genital Herpes Simplex Virus

HSV is the most common infectious cause of genital ulceration and should be your primary consideration for painful scrotal sores. 2, 3

• Primary HSV infection presents with painful vesicles or ulcers, often accompanied by systemic symptoms (fever, malaise) and inguinal lymphadenopathy. 3, 4
• Recurrent episodes are typically milder with localized lesions and fewer systemic symptoms. 3
• Diagnosis is confirmed by viral culture or PCR from lesion swabs, which are more sensitive than rapid antigen tests. 3
• Treatment with acyclovir effectively controls symptoms and improves healing, though it does not prevent future recurrences. 3
• Note that HSV can present atypically with severe cellulitis and prominent lymphadenopathy without obvious genital lesions initially. 4

Sexually Transmitted Infections

Obtain syphilis serology and HIV testing in all patients with genital ulcers. 5

• Syphilis can present as painless or painful ulcers (chancre) in primary stage. 5
• HPV infection causes condyloma acuminatum (genital warts), though these are typically painless unless secondarily infected. 5, 2
• Screen for gonorrhea and chlamydia if urethritis symptoms are present. 5

Bacterial Cellulitis

• Streptococcal cellulitis presents with erythema, warmth, swelling, and pain, often without a clear portal of entry. 1
• Requires immediate penicillin therapy and close monitoring for progression to necrotizing infection. 1

Inflammatory Dermatoses

Lichen Sclerosus

Lichen sclerosus is a chronic inflammatory condition that commonly affects the scrotum and presents with porcelain-white atrophic patches, areas of ecchymosis, and painful fissuring. 5, 2

• In males, it typically involves the prepuce, glans penis, and can extend to scrotal skin. 5
• Presents with tightening of skin, painful erections if foreskin involved, and may cause phimosis. 5
• Biopsy is mandatory if there are atypical features, treatment failure, or suspicion of malignancy (persistent hyperkeratosis, erosions, or new papular lesions). 5
• The striking ecchymosis seen in lichen sclerosus can be mistaken for trauma, but this does not exclude coincident sexual abuse. 5
• Long-term risk of squamous cell carcinoma exists, particularly in chronic untreated disease. 5

Other Dermatologic Conditions

• Psoriasis and lichen planus may have atypical appearance on scrotal skin due to moisture and maceration, lacking typical scales. 2
• Contact dermatitis (allergic or irritant) from condoms, lubricants, or hygiene products presents with erythema, pruritus, and sometimes vesicles. 2
• Plasma cell balanitis appears as smooth, shiny red-orange plaques but typically affects glans rather than scrotum. 2

Diagnostic Algorithm

Step 1: Assess for Surgical Emergency

• Examine for signs of necrotizing infection: rapid progression, severe pain out of proportion to exam, crepitus, skin necrosis, systemic toxicity. 1
• If present, obtain immediate surgical consultation without delay for imaging. 1

Step 2: Characterize the Lesions

• Vesicles or grouped ulcers: Think HSV—obtain viral culture or PCR. 3
• White atrophic patches with ecchymosis: Think lichen sclerosus—consider biopsy if diagnosis uncertain. 5
• Erythema, warmth, swelling without vesicles: Think bacterial cellulitis—start antibiotics. 1
• Painless ulcer: Think syphilis—obtain serology. 5
• Warty lesions: Think HPV—clinical diagnosis, biopsy if atypical. 5, 2

Step 3: Obtain Appropriate Testing

• Gram stain and culture of any discharge or lesion exudate. 5
• Syphilis serology and HIV testing in all cases of genital ulceration. 5
• HSV culture or PCR from vesicle fluid or ulcer base. 3
• Urinalysis and urethral swab for gonorrhea/chlamydia if urethritis present. 5
• Biopsy for chronic lesions, atypical presentations, or suspected malignancy. 5

Step 4: Initiate Empiric Treatment Based on Most Likely Diagnosis

For suspected HSV:

• Start acyclovir while awaiting culture confirmation. 3
• Provide supportive care with analgesics and scrotal elevation. 5

For suspected bacterial cellulitis:

• Penicillin for streptococcal infection, broader coverage if mixed flora suspected. 1
• Monitor closely for progression requiring surgical intervention. 1

For suspected STI:

• Treat empirically for gonorrhea and chlamydia if urethritis present: ceftriaxone 250 mg IM plus doxycycline 100 mg PO twice daily for 10 days. 5
• Ensure partner notification and treatment. 5

Critical Pitfalls to Avoid

• Do not dismiss rapidly progressive scrotal swelling as simple cellulitis—necrotizing infection requires immediate surgical debridement. 1
• Do not rely on rapid HSV antigen tests alone—viral culture or PCR is more sensitive and reliable. 3
• Do not assume lichen sclerosus is benign—long-term malignancy risk requires biopsy of suspicious areas and ongoing surveillance. 5
• Do not forget STI screening—obtain syphilis and HIV testing in all patients with genital ulcers regardless of appearance. 5
• Do not overlook asymptomatic HSV shedding—patients can transmit infection even without active lesions. 3

Follow-Up Considerations

• Reevaluate within 3 days if no improvement to reconsider diagnosis and treatment. 5
• Persistent swelling or tenderness after antimicrobial therapy completion warrants comprehensive evaluation for abscess, tumor, or fungal/tuberculous infection. 5
• Patients with confirmed STIs require partner notification within 60 days of symptom onset. 5
• Instruct patients to avoid sexual contact until both patient and partners complete treatment and are asymptomatic. 5