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.
