Treatment of Penile Shaft Swelling and Pus Discharge in Adults
Initiate empiric antibiotic therapy immediately with ceftriaxone 1 g IM/IV plus doxycycline 100 mg orally twice daily for 10 days, while simultaneously performing urgent diagnostic evaluation to rule out abscess formation that may require surgical drainage. 1
Immediate Diagnostic Evaluation
Perform the following tests before or concurrent with empiric treatment:
- Gram stain of urethral discharge to identify polymorphonuclear leukocytes (>5 per oil immersion field) and presumptively diagnose gonococcal infection 1
- Nucleic acid amplification test (NAAT) on first-void urine or urethral swab for N. gonorrhoeae and C. trachomatis 1
- Urethral swab culture before treatment initiation to assess antimicrobial resistance profiles 1
- Digital rectal examination to exclude perirectal abscess, which can present with penile discharge and swelling 2
- Imaging if abscess suspected: Ultrasound as first-line, but MRI with diffusion-weighted imaging is superior for distinguishing inflammatory tissue from abscess containing necrotic material 3
Age-Stratified Empiric Antibiotic Regimens
For Patients <35 Years (Sexually Transmitted Etiology Most Likely)
Primary regimen:
This targets C. trachomatis and N. gonorrhoeae, the predominant pathogens in sexually active younger men 1
For Patients ≥35 Years or Enteric Organism Suspected
Primary regimen:
- Ofloxacin 300 mg orally twice daily for 10 days OR
- Levofloxacin 500 mg orally once daily for 10 days 1, 4
These fluoroquinolones cover Gram-negative enteric organisms (E. coli) more common in older men or those with urinary tract abnormalities 1
For Cephalosporin/Tetracycline Allergies
Alternative regimen:
- Gentamicin 240 mg IM single dose PLUS azithromycin 2 g orally single dose 1
Surgical Intervention Criteria
Immediate surgical consultation and drainage required if:
- Fluctuant mass palpable on examination suggesting abscess 5, 2
- Failure to improve within 3 days of antibiotic initiation 1, 4
- Severe pain, fever, or signs of necrotizing infection 1
- Imaging confirms abscess formation 3
Critical pitfall: Penile abscesses can rupture spontaneously within 24 hours of presentation, and delayed drainage increases risk of complications including acute kidney injury from prolonged antibiotic exposure 5. Linear incisions for decompression prevent skin devascularization and gangrene 6.
Adjunctive Supportive Measures
- Bed rest, scrotal elevation, and analgesics until fever and inflammation subside 1, 4
- Avoid sexual intercourse until therapy completed and symptoms resolved 1, 4
Follow-Up and Reevaluation
Mandatory reassessment at 3 days:
- If no improvement, broaden differential to include tumor, testicular infarction, fungal infection (especially in immunocompromised), or Streptococcus intermedius abscess 1, 5
- Persistent swelling after completing antibiotics requires comprehensive evaluation including repeat imaging and possible biopsy 1
Management of Sexual Partners
For confirmed or suspected sexually transmitted infections, refer all sexual partners who had contact within 60 days preceding symptom onset for evaluation and treatment 1, 4
Special Populations
HIV-positive or immunocompromised patients:
- Use same antibiotic regimens as immunocompetent patients 1, 4
- Maintain higher suspicion for atypical organisms including fungi, mycobacteria, and Streptococcus intermedius 1, 4, 5
Geographic considerations:
- Check local quinolone resistance patterns before prescribing fluoroquinolones, particularly if infection acquired in Asia or Pacific regions 4
Rare Non-Infectious Etiology
If cultures remain negative and standard antibiotics fail, consider idiopathic penile abscess (possible pyoderma gangrenosum variant), which may respond to prednisolone 20-40 mg daily after definitively excluding infection 7. However, this diagnosis requires tissue histology showing no malignancy or bacterial infection 7.