Diagnostic Approach for Simple Cystitis

Definition and Diagnosis

The American College of Physicians and WikiGuidelines consensus strongly emphasizes that evidence-based diagnosis of UTI should be primarily based on clinical symptoms, not urinalysis, in healthy nonpregnant patients with typical symptoms of dysuria, frequency, urgency, and/or suprapubic pain, without systemic signs like fever 1, 2
Simple (uncomplicated) cystitis is characterized by the absence of systemic infection signs, such as no fever, flank pain, or costovertebral angle tenderness, and patient characteristics including healthy, immunocompetent, nonpregnant women with normal genitourinary anatomy 2
The positive predictive value of pyuria is exceedingly low because it indicates genitourinary inflammation from many noninfectious causes, with a low probability of confirming cystitis 1, 2

In simple uncomplicated cystitis in healthy nonpregnant patients, routine urine cultures are not necessary, but may be considered in patients with atypical symptoms or suspected pyelonephritis 1, 2
Urine cultures are reasonable for complicated cases and/or recurrent UTIs, suspected pyelonephritis, and pregnant patients, to guide targeted therapy 1, 2, 3
The absence of pyuria has good negative predictive value in most patient populations, making UA helpful in ruling out infection when negative 1, 2

For empirical treatment of uncomplicated cystitis, nitrofurantoin is a reasonable drug of choice based on robust evidence of efficacy and its ability to spare more systemically active agents 4
Do not rely solely on UA findings to diagnose or exclude UTI, and avoid routine UA and urine cultures for fever workup in hospitalized patients, as this leads to unnecessary testing and antimicrobial use 1, 2
Do not perform urine culture without accompanying urine microscopy due to common sample contamination and bacterial colonization 3