Young Woman With Dysuria and Increased Frequency and Urgency

A 21-year-old woman presents with a 3-day history of dysuria and increased urinary frequency and urgency. These symptoms began suddenly but have been worsening over the past few days. On the morning of her visit, she experienced some gross hematuria. She denies fever, chills, flank pain, or other systemic symptoms. She has not previously experienced similar or related symptoms.

HISTORY

She is a student at a local college and is in good health. Her menstrual history is normal, and she uses tampons, without recent changes in brand. She is sexually active and uses an oral contraceptive.

PHYSICAL EXAMINATION

The patient appears well and is in no acute distress. Vital signs, including pulse and temperature, are normal. Other than suprapubic pain on palpation, the results of the physical examination are normal.

LABORATORY RESULTS

A urine dipstick test performed in the office is positive for blood and leukocyte esterase.

Which of the following is the most appropriate statement about this patient?

A. She should be treated with trimethoprim-sulfamethoxazole (TMP-SMX), 160 mg and 800 mg, twice daily for 3 days.

B. The most likely pathogen is a toxigenic Escherichia coli.

C. Pre- and post-coital voiding patterns, liquid consumption, and tampon use are important risk factors for her condition.

D. She has pyelonephritis and should be admitted for parenteral antibiotic therapy.

Correct Answer: A

This patient exhibits the signs and symptoms of a urinary tract infection, and the choices presented are related to the classification and management of such infections. In the United States, urinary tract infections are the most common bacterial infections encountered in office practice.

CLASSIFICATION OF URINARY TRACT INFECTIONS

These infections are classified first as cystitis, infection of the lower genitourinary tract, or pyelonephritis, which is infection of the upper tract. Clues to the latter include fever (temperature of greater than 38°C [100.4°F]), chills, flank pain, and nausea and vomiting. This patient has none of these symptoms; she exhibits only the typical cystitis symptoms of dysuria and increased frequency and urgency. She does not have pyelonephritis, and choice D is thus
incorrect.

With either cystitis or pyelonephritis, the next issue is whether or not the infection is “uncomplicated” or “complicated.” Urinary tract infections are considered complicated when functional (eg, neurogenic bladder), anatomical (eg, stones), or metabolic (eg, diabetes) factors; multiple recurrences; or multidrug resistance is present.^1,2 Again, none of these seems evident in the case presented, and this fact helps direct therapy.

MICROBIOLOGY

The microbiology of uncomplicated cystitis (or pyelonephritis for that matter) is in 75% to 95% of cases caused by uropathogenic,¹ extraintestinal strains that possess properties which enhance their genitourinary tract pathogenicity, including flagella, toxins, and polysaccharide coatings that enable these organisms to overcome host defenses.¹ These E coli are extraintestinal and are not the toxigenic E coli that cause a variety of gastrointestinal syndromes. Thus, choice B is not correct.

RISK FACTORS

A variety of risk factors have been correlated with urinary tract infection. Those with true correlation include sexual intercourse, use of spermicides, and a new sex partner within the past year; while no significant association can be assigned to pre- or post-coital voiding pattern, liquid consumption, tampon use, wiping patterns, or type of underwear.^1,3 Thus, choice C is also incorrect.

TREATMENT

This patient seems to have a typical case of uncomplicated cystitis, almost assuredly with a uropathogenic E coli as the cause. A variety of effective therapies can be used according to current guidelines. The most convenient is a 3-day course of TMP-SMX, 160 mg and 800 mg, as offered in choice A. There is no reason given in the history to suggest any problem with resistance individually or epidemiologically (eg, prior therapy within 3 months or a known 20% or higher resistance rate of isolates). Nitrofurantoin is being more frequently used because it has fewer ecologic side effects; but this agent may cause more adverse effects in patients. Fluoroquinolones have more of both patient and ecologic side effects and should be reserved for empiric therapy of pyelonephritis or second-line therapy for cystitis.

OUTCOME OF THIS CASE

TMP-SMX was prescribed, and within 24 hours the patient’s symptoms resolved. At 1-year follow-up, she has not had a recurrence.n