What is the differential diagnosis of a patient presenting with dysuria?

Dysuria (a burning pain during urination) is a frequent complaint associated with a number of infectious and noninfectious etiologies. Dysuria is a common clinical manifestation of urinary tract infection (UTI), though its presence may vary based on the anatomic location of the infection along the urinary tract. Cystitis, which is a UTI localized to the bladder epithelium, classically presents with dysuria but may also present with concomitant urinary urgency, urinary frequency, change in urine color, malodorous urine, and/or suprapubic pain. Dysuria may also be caused by cervicitis (inflammation/infection of the cervix), urethritis (inflammation/infection of the urethra), vaginitis (inflammation/infection of the vaginal tract), interstitial cystitis (a chronic condition), as well as noninfectious vaginal or vulvar irritation. Frequent causes of cervicitis and urethritis include sexually transmitted infections such as Chlamydia trachomatis, Neisseria gonorrhoeae, and occasionally herpes simplex virus. Vaginitis may be infectious, such as with Trichomonas vaginalis, or associated with organism overgrowth, such as with Candida albicans or Gardnerella vaginalis.

Cystitis was mentioned as a type of UTI. What are the other types of UTIs?

UTIs can be classified based on anatomic parameters or clinical parameters. Lower UTIs involve the urethra (urethritis) or the bladder (cystitis). Upper UTIs involve the kidney (pyelonephritis) and include perinephric abscesses and renal abscesses. In men, prostatitis can also be considered an “upper” UTI.

UTIs can also be classified based on clinical parameters as either uncomplicated or complicated UTI. Uncomplicated UTI encompasses cystitis or pyelonephritis in nonpregnant women without any other structural or functional abnormalities of the urinary tract. In general, uncomplicated UTIs have a high likelihood of responding to empiric therapy. A complicated UTI includes essentially all other types of infections, both lower and upper tract, including those that occur in males, are associated with stones, involve urinary catheters, are associated with anatomic or functional abnormalities, or that occur after procedures or surgery.

What clinical clues help differentiate between the different types of UTIs?

There is considerable overlap in symptoms among the various types of UTIs; however, some historical elements can be distinguishing. As discussed earlier, cystitis typically presents with dysuria, urgency, and frequency but can also be associated with a change in urinary color, malodorous urine, and suprapubic pain. Fever is frequently absent, and finding fever usually suggests an upper UTI. Urethritis frequently is associated with discharge. In males, prostatitis is associated with symptoms of urinary obstruction, such as dribbling, hesitancy, a weak urinary stream, and incomplete voiding. Tenderness of the prostate or perineal pain may also be unique features.

Patients with pyelonephritis are frequently more toxic, with more systemic signs and symptoms, such as fevers, chills, back or flank pain, nausea, and vomiting. Symptoms of cystitis may or may not be present with pyelonephritis. Typically perinephric and renal abscesses have symptoms similar to pyelonephritis; however, they can be poorly responsive to antibiotic therapy alone.

Does the physical exam help narrow the differential diagnosis?

A thorough physical exam can help establish a diagnosis as the various causes of dysuria often manifest with characteristic findings. Cystitis most frequently presents with no specific findings, though suprapubic tenderness can be present. The presence of fever would suggest pyelonephritis, renal abscess, or perinephric abscess, all of which can be associated with costovertebral angle tenderness. The presence of genitourinary discharge would make cervicitis, urethritis, or vaginitis more likely. This patient has a benign physical exam and does not display any systemic signs of infection, suggesting a diagnosis of cystitis rather than an upper UTI or one of the other previously described causes of dysuria.