144 GU Infectious disease and getting more questions right

Urethritis

• Inflammation or infection of the urethra, usually from a sexually transmitted infection (STI).
• Most common pathogens: Chlamydia trachomatis and Neisseria gonorrhoeae.
• Can also result from chemical irritation or catheter use.

Risk Factors

• Multiple or new sexual partners
• Unprotected intercourse
• Prior STI history
• Men under 35 years old

Clinical Presentation

• Dysuria, burning, or itching at urethral meatus
• Urethral discharge:
  • Clear or mucoid → Chlamydia
  • Thick yellow-green → Gonorrhea
• Urethral redness or irritation
• The question stem would likely describe a young sexually active man with dysuria and discharge after unprotected sex.

Diagnostics

• NAAT (nucleic acid amplification test): Urethral swab or first-catch urine → most sensitive for Chlamydia and Gonorrhea.
• Urinalysis: Pyuria without bacteriuria (“sterile pyuria”) — WBCs in urine but no bacterial growth due to intracellular organisms like Chlamydia.
• Consider Trichomonas vaginalis or Mycoplasma genitalium if persistent symptoms.
• Screen for HIV and syphilis.

Treatment

• Empiric therapy for both C. trachomatis and N. gonorrhoeae:
  • Ceftriaxone 500 mg IM single dose
  • plus Doxycycline 100 mg PO twice daily for 7 days
• If doxycycline contraindicated → Azithromycin 1 g PO single dose
• Treat all sexual partners.
• Abstain from sexual activity for 7 days after treatment.
• Retest at 3 months due to high reinfection rate.

Exam Keys

• Dysuria + urethral discharge = Urethritis (STI until proven otherwise).
• Gonorrhea: Purulent yellow-green discharge.
• Chlamydia: Clear or mucoid discharge.
• Sterile pyuria: WBCs present but no bacterial growth → Chlamydia.
• Always treat both pathogens empirically.

Urinary Tract Infection (Cystitis)

• Infection of the bladder (lower urinary tract) most often caused by Escherichia coli.
• Common in women due to short urethra and proximity to anus.
• Classified as uncomplicated (healthy, nonpregnant women) or complicated (men, pregnancy, diabetes, obstruction, catheters).

Risk Factors

• Female sex, sexual activity, diaphragm or spermicide use.
• Postmenopausal estrogen loss, pregnancy, diabetes.
• Indwelling catheters or urinary obstruction (BPH, stones).

Clinical Presentation

• Dysuria, frequency, urgency, suprapubic pain, hematuria, cloudy urine.
• No systemic symptoms (no fever, chills, or flank pain).
• If fever or costovertebral tenderness → think pyelonephritis.
• The question stem would likely describe a young woman with burning urination, frequency, and no fever.

Diagnostics

• Urinalysis: Pyuria, positive leukocyte esterase, and nitrites (Gram-negative organisms).
• Urine culture: >100,000 CFU/mL of a single organism confirms diagnosis.
• Urine dipstick: Often sufficient in uncomplicated cases.
• Men or recurrent infections: Consider ultrasound to assess for obstruction or stones.

Treatment

• Uncomplicated: Nitrofurantoin, Trimethoprim-Sulfamethoxazole (TMP-SMX), or Fosfomycin.
• Pregnancy: Amoxicillin-clavulanate or nitrofurantoin (avoid TMP-SMX near term).
• Complicated or male patients: Fluoroquinolones (ciprofloxacin, levofloxacin).
• Encourage hydration and frequent voiding.
• Asymptomatic bacteriuria: Treat only in pregnancy, before urologic procedures, or within 3 months of renal transplant.

Exam Keys

• Dysuria + frequency + no fever = Cystitis.
• Fever or flank pain = Pyelonephritis.
• Positive nitrites = E. coli.
• Men or recurrent infections → evaluate for obstruction or stones.

Pyelonephritis

• Infection of the kidney and renal pelvis caused by ascending bacteria from the bladder.
• Most common pathogen: Escherichia coli.
• Represents an upper urinary tract infection (UTI).

Risk Factors

• Female sex, pregnancy, recurrent cystitis.
• Urinary obstruction (stones, BPH), vesicoureteral reflux.
• Diabetes, neurogenic bladder, indwelling catheters, immunocompromise.

Clinical Presentation

• Fever, chills, flank pain, and CVA tenderness (hallmark triad).
• Dysuria, urgency, and frequency.
• Nausea, vomiting, and malaise in moderate to severe cases.
• Older adults may present atypically with confusion or weakness.
• The question stem would likely describe a febrile patient with flank pain, CVA tenderness, and urinary symptoms.

Diagnostics

• Urinalysis: Pyuria, positive leukocyte esterase, positive nitrites, and WBC casts (upper tract finding).
• Urine culture: Confirms organism and guides therapy.
• CBC: Leukocytosis with left shift.
• Imaging (CT or renal ultrasound): Only if complicated infection, suspected obstruction, stones, or no improvement after 48–72 hours.

Treatment

• Outpatient (mild, stable): Oral fluoroquinolone (ciprofloxacin or levofloxacin) for 5–14 days.
• Inpatient (severe, vomiting, pregnant, or complicated): IV ceftriaxone, fluoroquinolone, or piperacillin–tazobactam.
• Switch to oral when afebrile and tolerating PO.
• Encourage hydration and follow-up urine culture after completion.

Exam Keys

• Fever + flank pain + WBC casts = Pyelonephritis.
• Cystitis = dysuria/urgency without fever or flank pain.
• WBC casts confirm upper tract involvement.
• Most common pathogen = E. coli.
• Hospitalize if pregnant, vomiting, or septic.

Epididymitis

• Inflammation or infection of the epididymis, usually unilateral.
• Caused by retrograde bacterial spread from the urethra or bladder.
• Most common cause of scrotal pain in adult men.

Risk Factors

• Sexually active men <35 → Chlamydia trachomatis or Neisseria gonorrhoeae.
• Men >35 or with urinary obstruction → E. coli or other coliform bacteria.

Clinical Presentation

• Gradual onset of scrotal pain and swelling (vs. torsion = sudden).
• Pain localized posteriorly to the testis (epididymis).
• Scrotal erythema and warmth; possible hydrocele.
• Fever and dysuria may occur.
• Positive Prehn sign: Pain relief with scrotal elevation.
• Cremasteric reflex preserved (absent in torsion).
• The question stem would likely describe a young man with dysuria and gradual testicular pain, improved with elevation.

Diagnostics

• Urinalysis: Pyuria and bacteriuria possible.
• NAAT: Detect C. trachomatis and N. gonorrhoeae in younger men.
• Scrotal ultrasound: Enlarged, hypervascular epididymis with increased blood flow (rules out torsion).
• Urine culture: For older men or suspected coliform infection.

Treatment

• Men <35 (STI-related):
  • Ceftriaxone 500 mg IM single dose plus Doxycycline 100 mg PO twice daily for 7 days.
• Men >35 or urinary obstruction:
  • Levofloxacin 500 mg PO daily for 10 days (covers E. coli).
• Scrotal elevation, NSAIDs, and rest for symptom relief.
• Treat sexual partners and screen for STIs when appropriate.

Exam Keys

• Gradual unilateral scrotal pain + Prehn sign + intact cremasteric reflex = Epididymitis.
• Sudden severe pain + absent reflex = Testicular torsion.
• <35 years: STI pathogens (Chlamydia, Gonorrhea).
• >35 years: E. coli or urinary pathogens.
• Always rule out torsion first.

Orchitis

• Inflammation or infection of the testis, often associated with epididymitis (epididymo-orchitis).
• Most common cause: viral (especially mumps).
• May also result from bacterial infection, usually secondary to epididymitis.

Risk Factors

• Postpubertal males with recent mumps infection (unvaccinated).
• Extension from epididymitis (bacterial cause).
• Sexually active men, urinary tract obstruction, or indwelling catheter.

Clinical Presentation

• Unilateral testicular pain and swelling.
• Testicular tenderness, erythema, and warmth.
• May follow parotitis by 4–7 days if due to mumps.
• Fever, malaise, and fatigue may occur.
• The question stem would likely describe a postpubertal male with recent parotitis who now has unilateral testicular pain and swelling.

Diagnostics

• Clinical diagnosis in classic mumps cases.
• Urinalysis and culture: If bacterial cause suspected.
• Ultrasound with Doppler: Increased blood flow differentiates from torsion.
• Mumps serology if uncertain or unvaccinated.

Treatment

• Viral (mumps): Supportive care — rest, scrotal elevation, NSAIDs, and ice packs.
• Bacterial: Treat same as epididymitis.
  • Ceftriaxone 500 mg IM single dose plus Doxycycline 100 mg PO twice daily for 7 days (<35 years, STI-related).
  • Levofloxacin 500 mg PO daily for 10 days (>35 years or urinary pathogens).
• Analgesics and supportive care for pain and swelling.

Exam Keys

• Unilateral testicular pain and swelling after mumps = Orchitis.
• Viral = supportive care; bacterial = antibiotics.
• Rule out torsion with ultrasound in any acute scrotal pain.

Prostatitis

• Inflammation or infection of the prostate gland.
• May be acute or chronic and either bacterial or nonbacterial.
• Most common urologic diagnosis in men under 50.

Types

• Acute bacterial: E. coli most common.
• Chronic bacterial: Recurrent infection by the same organism.
• Chronic pelvic pain syndrome (nonbacterial): Most common overall; culture negative.

Risk Factors

• Urinary tract infection or instrumentation (catheterization, cystoscopy).
• BPH causing obstruction.
• Unprotected intercourse or history of STIs.
• Dehydration or prolonged sitting (e.g., cycling).

Clinical Presentation

• Acute bacterial:
  • Fever, chills, malaise.
  • Dysuria, frequency, urgency, perineal or low back pain.
  • Tender, warm, “boggy” prostate on exam (avoid vigorous massage).
• Chronic bacterial:
  • Recurrent UTIs with the same organism.
  • Dull perineal discomfort, irritative voiding symptoms.
  • Often afebrile.
• Chronic pelvic pain syndrome:
  • Perineal pain and voiding symptoms for ≥3 months; cultures negative.
• The question stem would likely describe a man with fever, dysuria, and a tender prostate on exam.

Diagnostics

• Urinalysis and culture: Pyuria and bacteriuria in bacterial types.
• Prostatic massage: Contraindicated in acute prostatitis (may cause bacteremia).
• Post-massage urine or expressed prostatic secretions: Helpful in chronic bacterial cases.
• CBC: Leukocytosis in acute cases.
• PSA: Often elevated during infection — do not screen during acute phase.

Treatment

• Acute bacterial:
  • Ciprofloxacin or TMP-SMX for 4–6 weeks.
  • Hospitalize and start IV antibiotics (e.g., ceftriaxone, fluoroquinolone) if severe or septic.
  • Avoid prostatic massage.
• Chronic bacterial:
  • Fluoroquinolone or TMP-SMX for 6–12 weeks.
  • May require suppressive low-dose antibiotics.
• Chronic pelvic pain syndrome:
  • Alpha-blockers (tamsulosin), anti-inflammatories, warm baths, and pelvic floor therapy.
• Encourage hydration and stool softeners to reduce straining.

Exam Keys

• Fever + dysuria + tender “boggy” prostate = Acute bacterial prostatitis.
• Recurrent UTIs, dull pain, afebrile = Chronic bacterial prostatitis.
• Pain ≥3 months, negative culture = Chronic pelvic pain syndrome.
• Avoid prostatic massage in acute cases (risk of sepsis).
• E. coli is the most common bacterial cause.

Fournier Gangrene

• Necrotizing fasciitis of the perineum and genital region, rapidly progressive and life-threatening.
• Polymicrobial infection involving both aerobic and anaerobic bacteria.
• Most commonly affects men with diabetes, immunosuppression, or recent perineal trauma.

Risk Factors

• Diabetes mellitus (most common).
• Alcoholism, obesity, immunocompromise.
• Recent perineal, genital, or rectal surgery or trauma.
• Urethral stricture, indwelling catheter, or perirectal infection.

Clinical Presentation

• Rapidly progressing pain, swelling, and erythema of the scrotum, perineum, or lower abdomen.
• Pain out of proportion to physical findings is an early clue.
• Skin discoloration, crepitus (gas under the skin), and foul-smelling necrosis as infection advances.
• May develop fever, tachycardia, hypotension, or sepsis.
• The question stem would likely describe a diabetic male with severe perineal pain, swelling, and crepitus.

Diagnostics

• Clinical diagnosis — do not delay treatment for imaging.
• CT scan: May show subcutaneous gas, fascial thickening, or fluid tracking along fascial planes.
• Labs: Leukocytosis, elevated CRP, possible metabolic acidosis or acute kidney injury (AKI).
• Blood and wound cultures to guide antibiotic therapy.

Treatment

• Emergency surgical debridement — cornerstone of management; multiple surgeries often required.
• Broad-spectrum IV antibiotics:
  • Carbapenem or piperacillin–tazobactam plus clindamycin (to inhibit toxin production) plus vancomycin (for MRSA coverage).
• Aggressive IV fluids and hemodynamic support.
• Tight glycemic control.
• Hyperbaric oxygen therapy may be considered as an adjunct.

Exam Keys

• Diabetic male + perineal pain + crepitus = Fournier gangrene.
• Pain out of proportion is the classic early sign.
• Immediate surgical debridement + broad-spectrum antibiotics are lifesaving.
• Do not delay surgery for imaging.
• High mortality without prompt recognition and intervention.