Infectious Disease · Sexually Transmitted Infections
The facts most likely to be tested
Neisseria gonorrhoeae typically presents with copious, purulent, or mucopurulent discharge and a shorter incubation period.
Chlamydia trachomatis is the most common cause of nongonococcal urethritis and typically presents with scant, clear, or mucoid discharge.
Nucleic acid amplification testing (NAAT) is the gold standard diagnostic test for both *N. gonorrhoeae* and *C. trachomatis*.
Empiric treatment for gonococcal urethritis requires ceftriaxone 500 mg intramuscularly as a single dose.
Empiric treatment for nongonococcal urethritis requires doxycycline 100 mg orally twice daily for 7 days.
Mycoplasma genitalium should be suspected in cases of persistent or recurrent urethritis despite standard empiric therapy.
Disseminated gonococcal infection manifests as the classic triad of tenosynovitis, dermatitis, and polyarthralgia.
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A 24-year-old male presents to the clinic complaining of dysuria and penile discharge for the past 3 days. He reports having unprotected sexual intercourse with a new partner 1 week ago. Physical examination reveals copious, thick, yellow-green urethral discharge. A gram stain of the discharge shows gram-negative intracellular diplococci. He has no fever, joint pain, or skin lesions.
What is the most appropriate empiric treatment for this patient?
Ceftriaxone 500 mg intramuscularly
The patient's presentation of copious purulent discharge and gram-negative intracellular diplococci is diagnostic for gonococcal urethritis, which requires treatment with ceftriaxone.
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Etiology / Epidemiology
Primarily sexually transmitted in young, sexually active adults. Chlamydia trachomatis is the most common cause.
Clinical Manifestations
Presents with urethral discharge and dysuria. Morning drop is a classic sign of gonococcal infection.
Diagnosis
Nucleic acid amplification test (NAAT) is the gold standard. First-void urine is the preferred specimen.
Treatment
Ceftriaxone 500mg IM plus Doxycycline 100mg BID for 7 days. Treat sexual partners.
Prognosis
Untreated cases lead to pelvic inflammatory disease (PID) or infertility. Most resolve with prompt therapy.
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Epidemiology & Etiology
Most cases are caused by Neisseria gonorrhoeae or Chlamydia trachomatis. Unprotected sexual intercourse and multiple partners are the primary risk factors. Non-gonococcal urethritis (NGU) is frequently associated with Mycoplasma genitalium.
Pertinent Anatomy
The urethra serves as the common conduit for urine and semen in males. Inflammation of the mucosal lining leads to the characteristic dysuria and discharge seen in clinical practice.
Pathophysiology
Pathogens colonize the urethral epithelium, triggering an inflammatory response. This leads to the recruitment of neutrophils, resulting in purulent or mucopurulent discharge. If left untreated, the infection can ascend to the epididymis or prostate.
Clinical Manifestations
Patients report urethral discharge, dysuria, and urethral pruritus. Gonococcal urethritis typically presents with copious, opaque, yellow-white discharge. Chlamydial infection often presents with scant, clear, or mucoid discharge. Red flags include fever or flank pain, suggesting progression to pyelonephritis or systemic infection.
Diagnosis
The Nucleic acid amplification test (NAAT) is the gold standard for diagnosis due to high sensitivity and specificity. A first-void urine sample is required to maximize pathogen detection. Gram stain showing gram-negative diplococci is diagnostic for gonorrhea.
Treatment
Empiric treatment for gonorrhea is Ceftriaxone 500mg IM. For chlamydia, use Doxycycline 100mg BID for 7 days. Avoid sexual activity until 7 days after treatment completion. Contraindications include known severe allergy to cephalosporins.
Prognosis
Complications include epididymitis, prostatitis, and reactive arthritis (Reiter syndrome). Long-term sequelae include urethral strictures and infertility. Partner notification is mandatory to prevent reinfection.
Differential Diagnosis
Cystitis: suprapubic pain and urgency without urethral discharge
Prostatitis: tender, boggy prostate on digital rectal exam
Epididymitis: posterior testicular pain and swelling
Balanitis: inflammation of the glans penis
Herpes Simplex: painful genital ulcers rather than discharge