From the Guidelines
The most likely diagnosis for this 17-year-old girl is acute cystitis, a urinary tract infection (UTI) of the bladder, and treatment should begin with empiric antibiotics such as fluoroquinolones or cephalosporins, as recommended by the European Association of Urology guidelines 1.
Diagnosis and Treatment
The patient's presentation of hematuria and dysuria without fever or flank pain, along with urinalysis showing numerous red blood cells, white blood cells, and positive leukocyte esterase, supports the diagnosis of acute cystitis.
- The negative nitrite test does not rule out UTI as some pathogens do not convert nitrates to nitrites.
- According to the European Association of Urology guidelines 1, fluoroquinolones and cephalosporins are the only antimicrobial agents that can be recommended for oral empiric treatment of uncomplicated pyelonephritis, and by extension, acute cystitis.
- The patient should increase fluid intake and can take phenazopyridine 200 mg orally three times daily for 2 days to relieve dysuria symptoms.
- A urine culture should be obtained before starting antibiotics to identify the causative organism and its antibiotic sensitivities.
Considerations
While uncomplicated cystitis is most likely, other conditions to consider include:
- Sexually transmitted infections
- Urinary stones
- Interstitial cystitis if symptoms persist despite appropriate treatment
Follow-up
If symptoms do not improve within 48-72 hours of antibiotic therapy, the patient should return for reevaluation.
- The choice of antibiotic should be based on local resistance patterns and optimized 1.
- The European Association of Urology guidelines 1 provide a framework for the diagnosis and treatment of urinary tract infections, including acute cystitis.
From the Research
Patient Presentation
The patient is a 17-year-old girl presenting with bright red blood in the urine for 2 days, accompanied by dysuria but no trauma, fever, or flank pain. Her last menstrual period was 2 weeks ago, and she has regular menstrual periods.
Laboratory Results
Urinalysis shows:
- Protein: none
- Blood: 3+
- Leukocyte esterase: positive
- Nitrites: negative
- White blood cells: 20-30/hpf
- Red blood cells: 100+/hpf
Possible Diagnosis and Treatment
Based on the symptoms and laboratory results, the patient may have a urinary tract infection (UTI). According to the study by 2, the recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females is a 5-day course of nitrofurantoin, a 3-g single dose of fosfomycin tromethamine, or a 5-day course of pivmecillinam.
Treatment Options
Other treatment options for UTIs include:
- Oral cephalosporins such as cephalexin or cefixime
- Fluoroquinolones and β-lactams, such as amoxicillin-clavulanate
- Nitrofurantoin, fosfomycin, pivmecillinam, fluoroquinolones, cefepime, piperacillin-tazobactam, and carbapenems for UTIs due to AmpC-β-lactamase-producing Enterobacteriales
- Nitrofurantoin, fosfomycin, pivmecillinam, amoxicillin-clavulanate, finafloxacin, and sitafloxacin for UTIs due to ESBLs-E coli 2
Guideline Concordance
A study by 3 found that the overall concordance rate with Infectious Diseases Society of America guidelines for the treatment of uncomplicated urinary tract infections in women was 58.4%, with nitrofurantoin being one of the most commonly prescribed antibiotic agents. The study also found that patients aged 18 to 29 years and 30 to 44 years had a higher likelihood of receiving guideline-concordant treatment than patients aged 45 to 75 years.
Considerations
When selecting an antibiotic, factors to consider include pharmacokinetics, spectrum of activity, resistance prevalence, potential for adverse effects, and duration of therapy 4. Additionally, a study by 5 found that daily prophylaxis for recurrent UTI with 100 mg instead of 50 mg nitrofurantoin was associated with an equivalent hazard on UTI or pyelonephritis, and a higher hazard on cough, dyspnoea, and nausea, recommending 50 mg nitrofurantoin as daily prophylaxis.
Historical Context
Historically, sulfonamides, trimethoprim-sulfamethoxazole, nitrofurantoin, and nalidixic acid have been used to treat UTIs, with sulfonamides being the agent of first choice, and either nitrofurantoin or nalidixic acid as an alternative if sulfonamides cannot be tolerated 6.