Today, we’re examining a clinical case of a 30-year-old woman arrives at the clinic experiencing issues with dysuria. What’s the most likely diagnosis? Do you know the answer? Let’s find out!
A 30-year-old woman presents to the outpatient clinic with a four-day history of dysuria, increased urinary frequency and urgency, and a sensation of incomplete bladder emptying. She does not have a fever, flank pain, vaginal discharge or itching. She is not sexually active. Vitals are within normal limits. On examination, she has suprapubic tenderness, without rebound or guarding. There is no costovertebral angle tenderness. Urinalysis reveals leukocytes and leukocyte esterase, but no nitrites or blood. A clean-catch urine sample is sent for culture.
Which of the following is the most likely diagnosis?
A. Vaginal candidiasis
B. Gonococcal cervicitis and urethritis
C. Interstitial cystitis
D. Chlamydial cervicitis and urethritis
E. Cystitis
Scroll down for the correct answer!
The correct answer to today’s USMLE® Step 2 Question is…
E. Cystitis
Correct: See Main Explanation.
Incorrect Answer Explanations
A. Vaginal candidiasis
Incorrect: Vaginal candidiasis, or yeast infection, is often caused by antibiotic use, which disrupts the normal vaginal flora and allows for Candida overgrowth. Symptoms include itching and burning of the vagina, and a characteristic thick, white “cottage cheese-like” vaginal discharge.
B. Gonococcal cervicitis and urethritis
Incorrect: Neisseria gonorrhoeae is a common cause of sexually transmitted infections. Cervicitis and urethritis in women are commonly caused by Neisseria gonorrhoeae. With cervicitis, there is typically a mucopurulent discharge. Urethritis may also be seen concurrently and cause dysuria, however, most women with Neisseria gonorrhoeae are asymptomatic. This diagnosis is unlikely in this patient who is not sexually active.
C. Interstitial cystitis
Incorrect: Interstitial cystitis is a chronic condition characterized by bladder pain, urgency, frequency, and nocturia. Onset of symptoms in interstitial cystitis tends to be more insidious and chronic, rather than acute, as seen with this patient. The urine is sterile in interstitial cystitis.
D. Chlamydial cervicitis and urethritis
Incorrect: Chlamydia trachomatis is a sexually transmitted bacteria that can cause urethritis, leading to symptoms of dysuria. In women, chlamydial infection can also ascend to involve the cervix, producing a mucopurulent cervical discharge. While this patient does have dysuria, she has no vaginal discharge and is not sexually active.
Main Explanation
This patient has cystitis. Cystitis is a urinary tract infection (UTI) of the bladder/lower urinary tract and is most commonly caused by bacterial infections. Typical symptoms of cystitis include dysuria (painful urination), increased frequency of urination, urgency, a sensation of incomplete bladder emptying, and occasionally hematuria. The onset of symptoms tends to be acute onset, developing over a short period, which aligns with this patient’s 4-day history of symptoms. Physical examination may reveal suprapubic tenderness.
The urinalysis findings further support the diagnosis of cystitis. The presence of pyuria or leukocytes seen on urine microscopy indicates an inflammatory or infectious process within the urinary tract. White blood cell count ≥10 leukocytes/microL is consistent with a urinary tract infection. The presence of nitrites, produced by certain bacteria like E. coli, are often detected in bacterial UTIs, but their absence does not rule out a UTI, especially in the context of symptoms suggestive of cystitis. The presence of leukocyte esterase indicates a urinary tract infection since it is an enzyme released by leukocytes. A urine culture showing bacteriuria (≥105 colony-forming units/mL) of a uropathogen confirms the diagnosis.
Major Takeaway
Cystitis, or inflammation of the bladder, is typically caused by bacterial infections. Patients with cystitis typically present with dysuria and suprapubic tenderness. Urinalysis can show pyuria, positive nitrites, and hematuria.
Want to learn more about this topic?
Watch the Osmosis video: Lower urinary tract infection: Clinical sciences
References
- Michels, T., & Sands, J. E. (2015). Dysuria: Evaluation and Differential Diagnosis in Adults. American Family Physician, 92(9), 778–786.
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