Nonspecific Urethritis (NSU) – Notes (PSC Focused)

Nonspecific urethritis (NSU) is urethral inflammation not caused by Neisseria gonorrhoeae. It is usually due to other bacterial, viral, or non-infectious causes. This article has PSC Nepal focused notes on Nonspecific urethritis (NSU).

Etiology:

1. Infectious Causes:
2. Chlamydia trachomatis (most common)
3. Mycoplasma genitalium
4. Ureaplasma urealyticum
5. Trichomonas vaginalis
6. Herpes simplex virus (HSV)
7. Adenoviruses
8. Non-infectious Causes:
9. Chemical irritants (e.g., soaps, spermicides)
10. Trauma (e.g., catheterization, vigorous sexual activity)

Risk Factors:

1. Unprotected sexual intercourse
2. Multiple sexual partners
3. History of sexually transmitted infections (STIs)
4. Poor genital hygiene

Clinical Features:

1. Urethral discharge (clear, mucoid, or purulent)
2. Dysuria (burning sensation while urinating)
3. Urethral pruritus or discomfort
4. Possible hematuria (rare)
5. Symptoms may be mild or asymptomatic in some cases

Diagnosis:

1. Clinical Diagnosis: Based on symptoms and exclusion of gonorrhea
2. Laboratory Tests:
3. Urinalysis (pyuria without bacteriuria)
4. Gram stain of urethral discharge (absence of intracellular diplococci)
5. Nucleic Acid Amplification Test (NAAT) for Chlamydia trachomatis and Mycoplasma genitalium
6. Culture for Ureaplasma and Mycoplasma (if available)

Differential Diagnosis:

1. Gonococcal urethritis
2. Prostatitis
3. Cystitis
4. Epididymitis

Management:

1. Empirical Antibiotic Therapy:
2. First-line:
3. Azithromycin 1g single dose OR
4. Doxycycline 100mg BID for 7 days
5. Alternative:
6. Moxifloxacin 400mg daily for 7-14 days (if M. genitalium is suspected and resistant to doxycycline)
7. Adjunct Measures:
8. Avoid sexual intercourse until symptoms resolve and treatment is completed
9. Partner notification and treatment (to prevent reinfection)
10. Follow-up in 2-4 weeks if symptoms persist

Complications:

1. Chronic urethritis
2. Epididymitis
3. Reactive arthritis (Reiter’s syndrome)
4. Infertility (rare)

Prevention:

1. Safe sexual practices (consistent condom use)
2. Regular STI screening
3. Avoidance of potential chemical irritants