The correct answer is D

The correct answer is C

The correct answer is B

The correct answer is B

The correct answer is A

Comment: Bladder capacity (ounces) = age (years) + 2 predicts normal bladder capacity.

VUR, a congenital anomaly characterized by either a unilateral or bilateral reflux of urine from the bladder to the kidneys, is common in young children. Approximately 30% of children younger than 5 years of age with VUR are identified by routine voiding cystourethrogram after UTI, and 9% to 20% of prenatal hydronephrosis with VUR are detected postnatally. For most, VUR resolves spontaneously. About 20% to 30% will have further infections, and only a few will experience long-term renal sequelae.

It is well known that the severity of renal scarring is associated with the severity of VUR. Previous studies have identified that the older age of VUR diagnosis (≥5 years), higher grade of VUR, and higher number of UTIs were risk factors for renal scarring. Similarly, other studies showed a direct relationship between male sex, high-grade VUR, and renal dysplasia. Thus, efforts to prevent renal scarring should be directed toward a rapid diagnosis and treatment of VUR.

Few reports have focused on the prevalence and risk factors for deteriorating renal function associated with VUR. According to data from North American Pediatric Renal Trials, there is an estimate of 3.5% to 5.2% of children in renal replacement therapy because of VUR nephropathy.

In addition to the prevalence of chronic kidney disease (CKD) among VUR patients, findings regarding the predictive risk factors for the development and progression of CKD in children with VUR have been conflicting; furthermore, it is debated whether VUR is a benign or nonbenign condition. Grade V VUR, bilateral renal damage, and a delay in the diagnosis of VUR 12 months after UTI were independent predictors of CKD. The older the age, the higher the CKD stage and the history of UTI are significant risk factors for CKD progression in children with VUR.

Renal function deterioration tends to be inversely correlated with the increasing degree of VUR and bladder dysfunction.

The correct answer is F

Comment: VUR is a condition in which urine flows backward from the bladder into the ureters during urination. VUR is found in 35% of children who have a UTI with fever. When children have recurrent UTIs, VUR is thought to increase the risk of kidney damage.

In most children, reflux is a birth defect caused by an abnormal attachment between the ureter and bladder with a short, ineffective valve. In some children, an infrequent urination pattern may cause reflux to occur. A child with VUR is more likely to develop a kidney infection, which can lead to kidney damage.

Because VUR does not cause pain, discomfort, or problems with urination, it is a silent abnormality that usually goes undetected unless there is a UTI. The average age of diagnosis is 2 to 3 years, and approximately 75% of children treated for reflux are girls.

Although surgery is sometimes required, reflux will often gradually disappear by age 5 or 6 years. Imaging studies can determine the grade of the VUR condition. High grades of VUR may require a daily low dose of an antibiotic, given, sometimes for several years, in hope of preventing recurrent UTIs and kidney damage.

The correct answer is D

Comment: Febrile infants with UTIs should undergo renal and bladder ultrasonography to detect anatomic abnormalities that require further evaluation.

VCUG should not be performed routinely after the first febrile UTI; VCUG is indicated if renal bladder ultrasound (US) reveals hydronephrosis, scarring, or other findings that would suggest either high-grade VUR or obstructive uropathy, as well as in other atypical or complex clinical circumstances. Further evaluation should be conducted if there is a recurrence of febrile UTI.

Probiotics are effective and safer than antibiotics at reducing the risk of recurrent UTI in children with a normal urinary tract after their first episode of febrile UTI.

The correct answers are A and B

Comment: The presence of hydronephrosis is highly suspicious of either ureteropelvic junction, obstruction, hydrometer, or VUR.

The correct answers are A and D

Comment: The most likely diagnosis in this patient is a UTI, specifically, acute cystitis. Classic UTI symptoms include urinary frequency urgency and dysuria. Other complaints could include suprapubic pain or discomfort, hesitancy, nocturia, and even gross hematuria. Urinary tract infections are classified by the anatomical location in which the infection and inflammation occur. Risk factors that this patient possesses, which will be discussed later, are female sex, age, recent sexual activity, and a history of prior UTI, which we can infer from her report of previous similar symptoms.

Vaginitis and cervicitis should also be considered in this patient given her history of sexual activity. However, the patient has no reported vaginal discharge or signs of these infections on the pelvic examination. Another important diagnosis to consider is pyelonephritis, which involves infection of the upper urinary tract. This is also not likely given her lack of fever, flank pain, and other key symptoms which will be discussed in a later section.

The correct answer is D

Comment: Urinary tract infections are due to the colonization of the urinary tract by microbes. Certain populations are at higher risk of infections of the urinary tract. Women are among those most affected by UTIs, with a lifetime incidence rate of almost 50%. The difference between the sexes is attributed to women’s shorter urethral length. Women who are sexually active are also at risk of UTI because of the proximity of the urethral meatus to the flora-rich anus. If the patient is a premenopausal, otherwise healthy, and nongravid female, as in this case, she has developed an “uncomplicated” infection.

Patients who are predisposed to conditions that make colonization more likely or are exposed to microbes that are more facile in evading the body’s natural protective mechanisms are more apt to contract UTIs, and their infections can be more difficult to treat. These patients have “complicated” infections. Numerous conditions make a patient more susceptible to UTI. These include underlying medical problems or structural abnormalities of the urinary tract such as urinary obstruction, vesicoureteral reflux, underlying urinary tract disease, diabetes, renal papillary necrosis, immunosuppression (medically induced or as a result of HIV infection), treatment with antibiotics, pregnancy, menopause, and spinal cord injuries.

The elderly are also at increased risk of UTI, particularly men, many of whom develop obstructive uropathy from benign prostatic hypertrophy.

The correct answers are A, B, and D

Comment: According to the Infectious Diseases Society of America, both clinical and laboratory criteria should be met to make the diagnosis of a CAUTI. The patient should have signs or symptoms of a UTI and no other known source of infection. Culture of the patient’s urine sample should yield greater than 103 CFU/mL of at least one species of bacteria. The cultured urine should be from a single specimen in those patients who are still catheterized. CAUTI can also be diagnosed in those who have had a catheter removed within the preceding 48 hours, in which case a midstream voided urine is the appropriate specimen.

CAUTIs are a type of complicated UTI and are among the most common nosocomial (hospital-acquired) infections in the United States. Urinary catheters facilitate the ascent of microbes into the urinary tract. There are different methods of catheterization: for example, clean intermittent catheterization, indwelling urethral catheters, and suprapubic catheters. Microorganisms can be introduced during the procedure of catheterization despite implementing sterilization methods. Also, without appropriate catheter care, these indwelling devices can become a nidus for infection, permitting various other flora to travel along the tube and into the urinary tract.

Escherichia coli is the most common causative organism of acute cystitis in uncomplicated UTIs. It is also the most commonly isolated organism in CAUTI. However, patients with catheters are at higher risk of infection by organisms less commonly seen in noncatheterized patients. Patients who are catheterized for both short and long periods are at increased risk of infection with fungal organisms as well as Enterobacteriaceae such as Klebsiella , Serratia , Enterobacter , Pseudomonas , Enterococcus , and Proteus species. These organisms are exceptionally well adapted for invasion given the ability many of them possess to form biofilms. The longer a patient is catheterized, the more likely they are to develop bacteriuria, a symptomatic infection, and potentially colonization of the urinary tract. Thus, timely removal of catheters when no longer necessary is wise.

The correct answers are A, B, and C

Comment: Laboratory tools are commonly used in the investigation of UTIs for patients with a complicated UTI, recurrent infections, or an unclear diagnosis based purely on history and physical examination. Again, test results should always be correlated with clinical findings because false-positive or false-negative results can occur through multiple avenues. Available tests include a urine dipstick, urinalysis with microscopy, and culture and gram stain with sensitivity testing. The first two of these have the potential to be performed in physicians’ offices. A clean-catch midstream specimen should be submitted to avoid contamination from vaginal or penile microorganisms. Patients should be given a 2% castile soap towelette and instructed in appropriate specimen collection. Men should cleanse the glans, retracting the foreskin first if uncircumcised. Women should cleanse the periurethral area after spreading the labia. Identification of lactobacilli and epithelial cells from the vagina suggest contamination.

General features of the urine can first be examined to include the color, clarity, and odor; but these features are nonspecific. For example, cloudy urine can be caused by the presence of white blood cells (WBCs) and/or bacteria in a UTI, but it can also be caused by numerous other pathologic and nonpathologic substances.

Urine dipstick studies, primarily searching for leukocyte esterase and nitrites, are useful when the pretest probability of UTI is high. Leukocyte esterase is an enzyme possessed by WBCs; thus, a positive urine dipstick for leukocyte esterase indicates the presence of inflammatory cells in the patient’s urinary tract. Inflammatory cells in the urine are not specific for a UTI because leukocytes can also be present in other situations such as glomerulonephritis and vaginal contamination. Nitrite is a breakdown product of nitrates, which are normally found in a healthy patient’s urine. The dipstick test for nitrite is specific for gram-negative organisms that possess an enzyme enabling them to reduce nitrates. It follows, then, that this test is less useful in the setting of potential gram-positive microbe infection. Also notable is that the nitrite test can be falsely negative in a patient with abundant fluid intake and frequent urination. Multiple other factors including medications, diet, and specimen handling can affect urine dipstick results, such as inappropriate handling or expiration of test strips.

Urinalysis with microscopy provides a window into the kidney and urinary tract. The presence of red blood cells, WBCs, casts, crystals, and bacteria aid in many diagnoses. Specific to UTI, the presence of WBCs and red blood cells indicates inflammation and, potentially, infection in the urinary tract. Pyuria, the presence of leukocytes in the urine, is not specific to UTIs as noted previously, but the absence of leukocytes should cause one to question a diagnosis of UTI unless the culture is positive. The identification of crystals might suggest the presence of renal calculi, which can serve as a nidus for infection. In fact, some stones (e.g., struvite) are the direct result of infection with urea-splitting organisms. Overall, urinalysis is useful; however, the clinical history still plays a key role to avoid under- and overdiagnosis.

Urine culture is the gold-standard diagnostic tool for diagnosing UTIs. As stated previously, in patients with a convincing clinical history and physical examination consistent with uncomplicated cystitis, no culture is necessary. However, in patients with complicated, severe upper urinary tract, or recurrent, UTIs, urine culture should not be foregone, because it is necessary for determining the causative organism and, consequently, for guiding appropriate therapeutic intervention. Furthermore, growth of the organism in culture facilitates sensitivity studies, in which pharmacologic agents are tested on the microbe isolated from the patient. This testing provides medical personnel with information regarding the efficacy of potential therapeutic options in the form of minimal inhibitory concentrations. This information guides the narrowing of antibiotic choice from whichever broad-spectrum treatment was initiated when a UTI was first suspected. Some organisms such as Ureaplasma may not be grown on routine cultures, so a false-negative result is possible. False-positive results are rare, other than from contamination, which should be suspected in most cases with the growth of multiple types of bacteria or vaginal flora.

The correct answers are A, B, C, and D

Comment: Infection of the kidney is termed pyelonephritis . These patients tend to present acutely with “upper tract signs,” including fever, chills, flank pain, and CVA tenderness. Symptoms of lower UTI can also be present; however, this is not usually the case. The clinical presentation may vary and can be life-threatening. In the most severely ill, patients may present in septic shock, with hypotension, tachycardia, and tachypnea, especially when infected with a gram-negative organism.

The correct answers are A, B, C, D, and E

Comment: Urinary tract infections can be complicated by several conditions depending on the severity and chronicity of the infection and the implicated organism. Severe upper UTIs can lead to acute kidney injury and, if not treated, can lead to permanent kidney damage and fibrosis. Similarly, upper UTIs can be complicated by renal or perinephric abscesses. Renal abscesses are mostly found in patients with preexisting kidney disease. Patients infected by a urea-splitting organism are at risk of struvite stones, which are commonly found in the upper urinary tract.

The correct answers are A, B, C, D, and E

Comment: The choice of therapy for a UTI depends on the clinical treatment setting and whether it is a complicated or uncomplicated UTI. An optimal outpatient antibiotic can be taken orally, has a tolerable side effect profile, and is concentrated to a therapeutic level in the patient’s urine. Antibiotics that fit this profile are appropriate to give patients who have a low risk for infection with a multidrug-resistant strain. Options for therapy include nitrofurantoin monohydrate, trimethoprim-sulfamethoxazole, fosfomycin, and pivmecillinam.

Recent infectious disease guidelines reflect growing concern for infection with multidrug-resistant organisms. When therapy needs to be escalated because of infection with a multidrug-resistant organism or tissue-invasive disease with bacteremia, options remain for oral therapy. In these situations, it is advantageous to obtain urine culture and microbe antibiotic sensitivities to better eliminate the infection. If hospitalization is indicated and the patient requires parenteral antibiotics, empiric therapy should be initiated. After microorganism sensitivities return, antibiotic therapy can be narrowed to one of the following: a carbapenem, third-generation cephalosporin, fluoroquinolone, ampicillin, or gentamicin.

Pharmacotherapy for complicated UTIs should begin with broad-spectrum therapy and then be narrowed by sensitivities when possible. The grouping that places the patient in the “complicated” category plays a role in treatment selection. For example, UTIs in men typically involve the prostate as well as the bladder, so treatment should target the infection in both organs. Patients who are pregnant require antibiotics that are safe for the fetus. Some complicated UTIs, especially in the case of upper UTIs, are managed in an inpatient setting with intravenous antibiotics because of the presence of tissue-invasive disease or bacteremia. In this case, the concentrations of antibiotic in the blood and the urine are important. This differs from the treatment of uncomplicated UTIs, which are dependent on the concentration of the pharmacotherapeutic agent in the urine.

Potential correction of modifiable risk factors for UTIs, if present, can also be addressed to prevent recurrent infection. This may include correction of an anatomic or structural abnormality of the urinary tract, consideration of alternative birth control types in a woman who uses a diaphragm with spermicide, removing a urinary catheter, or simply counseling a woman to attempt urination after sexual intercourse.

The correct answers are A, B, C, and D

Comment: In general, gram-negative aerobic rods are the most commonly isolated pathogens implicated in UTIs. Escherichia coli is the most common causative organism of UTIs, especially in sexually active young women. Microorganisms such as uropathogenic E. coli with an enhanced ability to bind and to adhere to urinary tract epithelia are more capable of causing infection. Adhesins and pili resistant to the innate immune mechanisms of defense are among the advantageous traits that particularly virulent strains of uropathogenic E. coli possess.

A variety of other Enterobacteriaceae are also found in the setting of CAUTIs. However, gram-positive organisms are clinically significant in some settings. Staphylococcus saprophyticus is not infrequently implicated in uncomplicated UTIs in young, sexually active women. Group B Streptococcus ( Streptococcus agalactiae ) is of particular concern in pregnant patients. In one prospective study, Group B Streptococcus was the second most isolated pathogen behind E. coli in the urine of asymptomatic bacteriuric pregnant women. Screening pregnant women for asymptomatic bacteriuria plays an important role in decreasing the risk of pyelonephritis during pregnancy.

The correct answer is B

Comment: The diagnosis of asymptomatic bacteriuria requires two criteria: (1) the urine is culture-positive; and (2) the patient does not have symptoms or signs of a UTI. The level of bacteria in culture should reach ≥105 CFU/mL, although it can be lower in catheterized patients (≥102 CFU/mL). Asymptomatic bacteriuria is only treated in some groups of patients, including those who are pregnant or undergoing urologic procedures because it otherwise does not correlate with symptomatic disease or complications.

The correct answer is D

Comment: Self-treatment of each infection with nitrofurantoin is appropriate for this patient (option D). One-quarter to one-third of women who recover from an episode of cystitis will develop another symptomatic infection within 6 months. Recurrent infections that return within 2 weeks of finishing appropriate antibiotic therapy for uncomplicated cystitis and involve the same cultured bacteria are categorized as relapsed.

Recurrent UTIs occurring weeks after successful antibiotic treatment and often involving bacterial strains different from the original are termed reinfections . This type of recurrent UTI is defined by three culture-positive infections in the previous 12 months or two infections within 6 months. Contributing factors for reinfection in premenopausal women include sexual activity, diaphragm and spermicide use, delayed urinary habits, and douching. Diminished estrogen levels and, to a lesser extent, increases in residual bladder urine volume and incontinence play much larger roles in UTIs in postmenopausal women. Episodic self-diagnosis and treatment with a first-line, short-course regimen such as nitrofurantoin is an appropriate initial strategy. Single-dose postcoital antibiotics are effective in reducing bladder infections if infection is temporally related to coitus; avoidance of spermicides has also proven beneficial.

Anecdotal claims of the benefits of ingestion of daily cranberry juice or tablets (option A), presumably by inhibiting the adherence of E. coli to uroepithelial cells, lack randomized clinical trial confirmation.

Adhesion blockers such as D-mannose (option B), theorized to block E. coli adhesion to mannosylated uroepithelial receptors, have not been tested in clinical trials.

Antimicrobial prophylaxis should be reserved for women with frequent recurrent cystitis, defined as three or more infections within 12 months that have not lessened after attempts using nonantimicrobial strategies.

Placebo-controlled trials using nightly doses of antibiotics demonstrated an approximate 95% reduction in infection recurrence. A 6-month trial is recommended; however, the previous pattern of recurrent infection occurs in nearly 50% of women when antibiotic prophylaxis is discontinued. Preferred prophylactic regimens include nitrofurantoin (50–100 mg), trimethoprim-sulfamethoxazole (single strength), and cephalexin (125–250 mg). Ciprofloxacin (option C) or other fluoroquinolone antibiotics are no longer recommended because of long-term safety concerns.

Urination soon after sexual intercourse (option E) is often recommended but is an unproven strategy to prevent recurrent UTI.

The correct answer is B

Comment: Options A, C, and D are commonly associated with other types of infections.

The correct answer is D

Comment: Maintaining a sterile, closed unobstructed urinary drainage should be used with indwelling catheters. The indwelling catheter and collecting system should not be disconnected. Breaking the collecting system to obtain urine specimens for analysis and bacterial culture should be avoided. To obtain urine specimens, the sampling port for the urine collection must be used (option D is correct).

Most studies suggest that antimicrobial prophylaxis is not useful in the prevention of CAUTIs in asymptomatic patients (option A is incorrect).

Urethral cleaning with povidone-iodine solution or soap and water has not been shown to prevent CAUTIs. There is evidence that frequent urethral cleaning can lead to mucosal irritation and breakdown that may increase the risk of infection (option B is incorrect).

Antibiotic-coated catheter has not been shown to decrease CAUTIs and should be used as a routine prevention measure (option C is incorrect). Routine irrigation with normal saline or antibiotic-containing solution should be avoided unless obstruction is suspected (option E is incorrect).

The correct answer is E

Comment: In 2016, the American Academy of Pediatrics (AAP) reaffirmed its 2011 UTI clinical practice guideline and recommended that VCUG should not be performed routinely after the first febrile UTI and indicated that VCUG is warranted if renal US reveals hydronephrosis, scarring, or other findings that would suggest either high-grade VUR or obstructive uropathy.

Furthermore, AAP recommended that antimicrobial prophylaxis should not be given to children aged 2 to 24 months after their first febrile UTI if the results of renal and bladder ultrasonography are normal. According to the AAP guidelines, the use of routine antibiotic prophylaxis seems to be ineffective in preventing the recurrence of febrile UTI and also it promotes the growth of bacterial-resistant microorganisms.

The high recurrent UTI rates in infants and young children increase the potential risk for the development of bacterial resistance, as has been reported in a recent randomized controlled clinical trial.

The study results concluded that probiotic compared to no treatment (placebo) was more effective in preventing UTI recurrence after the first febrile UTI in young children with normal urinary tract system (option E).

The correct answer is A

Comment: UTI associated with urinary upper tract dilatation should be given prophylactic antibiotics and undergo further imaging studies including a diuretic renogram or VCUG if clinically indicated.

The correct answers are A, B, C, D, and E

Comment: Acute UTIs are relatively common in children. The most common pathogen is E. coli , accounting for approximately 85% of UTIs in children. Renal parenchymal defects are present in 3% to 15% of children within 1 to 2 years of their first diagnosed UTI. Clinical signs and symptoms of a UTI depend on the age of the child, but all febrile children aged 2 to 24 months with no obvious cause of infection should be evaluated for UTI (with the exception of circumcised boys older than 12 months). Evaluation of older children may depend on the clinical presentation and symptoms that point toward a urinary source (e.g., leukocyte esterase or nitrite present on dipstick testing; pyuria of at least 10 WBCs per HPF and bacteriuria on microscopy). Increased rates of E. coli resistance have made amoxicillin a less acceptable choice for treatment, and studies have found higher cure rates with trimethoprim-sulfamethoxazole. Other treatment options include amoxicillin-clavulanate and cephalosporins. Prophylactic antibiotics do not reduce the risk of subsequent UTIs, even in children with mild to moderate vesicoureteral reflux. Constipation should be avoided to help prevent UTIs. Ultrasonography, cystography, and a renal cortical scan should be considered in children with UTIs. Options A, B, C, D, and E are in agreement with the AAP’s Clinical Practice Guideline. ^,

The correct answer is A

Comment: UTI in men without an indwelling urethral catheter is uncommon. Once a male patient is confirmed to have a first UTI, evaluation of the upper and lower urinary tract is recommended given the high prevalence of urologic abnormalities among men who present with a UTI. Residual urine volume should be assessed by means of noninvasive ultrasonography. Although there is no clear cutoff, a residual volume exceeding 100 mL raises suspicion for a urinary tract obstruction distal to the bladder.

Either computed tomography with intravenous contrast or ultrasonography is the diagnostic modality of choice in evaluating the anatomy of the urogenital tract. These investigations are especially high yield in febrile UTI cases. ^,

The correct answer is A

Comment: According to the AAP, renal-bladder US is mandated for screening after the first febrile UTI. Voiding cystourethrogram should be obtained if screening US demonstrates collecting system dilatation or renal parenchymal abnormality, or if second febrile UTI occurs. A renal DMSA nuclear scan should be obtained either acutely or within 3 months if screening US shows cortical thickening and irregularities or if a second febrile UTI occurs. A DMSA nuclear scan will indicate upper tract involvement by photopenic areas, which may become areas of permanent scar or may return to normal by the 3 months.

A clean-catch urine test positive for leukocyte esterase, nitrites, blood, and containing 50 to 100 WBC/HPF and bacteria under microscopic examination should be considered highly suspicious of bacterial infection and warrant imperative intravenous antibiotic therapy.

Ideally, there is a need to obtain a catheterized sample for culture, so that there would be no question about the diagnosis because of significant implications for the child/workup.

If unable to catheterize, send the sample for culture. In any case, >50,000 CFU/mL of a single pathogen confirms the diagnosis of pyelonephritis.

Most community UTIs are E. coli , but about half may be resistant to ampicillin/amoxicillin. Therefore, you could choose first-generation cephalosporin or trimethoprim-sulfamethoxazole; adjust after culture/sensitivity.

Consider the patient’s age and ability to clear the antibiotic (e.g., renal, hepatic function) when selecting a medication. Consult institutional antibiogram for local pathogens and antibiotic coverage.

Await culture (48–72 hours to result). Support symptom amelioration with analgesics, increased fluids, and antipyretics.

Repeat culture or urinalysis for test of cure is not indicated in the absence of persistent symptoms.

If a structural abnormality is suspected or found on US, you may want to proceed to VCUG. If VUR is detected and US demonstrates upper tract dilation, initiate prophylactic antibiotics. However, avoid using prophylactic antibiotics in a child with the first febrile UTI with normal kidney-bladder US. In this situation, consider a nonantibiotic, probiotic therapy.

In older children, check for functional bladder or bowel dysfunction and aggressively work on correcting constipation, elimination avoidance behaviors, and hydration. Failure to correct will lead to continued risk of UTI, no matter what else may be wrong. ^,

The correct answer is C

Comment: Although the patient meets the criteria for a UTI, it is not a CAUTI because no indwelling catheter was present in the 48 hours before the infection. An indwelling catheter is defined as a “drainage tube that is inserted into the urinary bladder through the urethra.” A condom catheter does not meet this definition. ^,

The correct answer is A

Complicated UTI is defined as when the infection is associated with obstructive hydronephrosis, hypertension, impaired renal function, or vesicoureteral reflux.

The correct answers are A, D, and I

Comment: History and physical findings are consistent with the diagnoses of a UTI and dysfunctional elimination syndrome. The urinalysis is both leukocyte and nitrite positive.

How a specimen is collected directly correlates to its validity: the most valid is suprapubic bladder aspirate, the second is sterile urethral catheterization, and the third is clean-catch midstream. The least reliable is the bagged specimen.

The patient has no known allergies. She has delayed voiding, posturing to prevent enuresis, and constipation, which are symptoms consistent with dysfunctional elimination syndrome. There is one documented upper UTI with fever, nausea, and vomiting. Pyelonephritis may be indicative of structural abnormality and warrants additional evaluation. Structural abnormalities such as VUR, obstruction, or other anatomical defects may present as UTIs.

In children, it is important to discover anatomical sources for bacterial persistence that may necessitate surgical intervention. A renal and bladder US should be obtained in any child with a febrile UTI and a VCUG should be obtained in children with hydronephrosis and in children with the second febrile UTI.

The correct answer is A

Comment: The patient should be started on antibiotics empirically. Two months ago, she was seen in the emergency department at which time her urine specimen grew greater than 100,000 colonies of K. pneumoniae . She was treated with a single dose of ceftriaxone and discharged on oral cephalexin. The culture was sensitive to the prescribed treatment and sulfamethoxazole. On this admission, her clinical symptoms are consistent with a lower tract bladder infection; she does not have fever, flank pain, nausea, or vomiting, which are symptoms of pyelonephritis. She is started on trimethoprim-sulfa; when she finishes the treatment dose, she will be started on prophylaxis. Trimethoprim-sulfa is a good choice; it is inexpensive, does not need to be refrigerated, has a relatively long shelf life, and is unlikely to cause gastrointestinal upset. The side effect profile overall is low.

Trimethoprim-sulfamethoxazole can be used in children older than 2 months of age. The treatment dose is based on trimethoprim 6 to 12 mg/kg/day given twice per day for 10 days. The prophylaxis dose is also based on trimethoprim, but at 1 to 2 mg/kg/day. Trimethoprim-sulfamethoxazole diffuses into vaginal fluid and decreases bacterial colonization.

Macrodantin or Furadantin elixir is another effective treatment and/or prophylactic agent. It does not achieve high blood levels and should not be used for systemic or febrile infections. The most common side effect is gastrointestinal upset. To help prevent this problem, the medication should be given with food. The liquid form is not tolerated well by children. The capsules can be opened and sprinkled on applesauce, yogurt, or pudding. It can be given to children older than 2 months of age, and the treatment dose is 5 to 7 mg/kg/day given four times per day. Prophylaxis is 1 to 2 mg/kg/day in a single dose.

Amoxicillin is also used to treat urinary tract infections and is often used for prophylaxis in children younger than 3 months of age. It is tolerated well and has a low side effect profile but can cause candidiasis in high doses. The suspension has to be refilled every 14 days, which makes it less convenient for families to use. Prophylaxis is 20 mg/kg/day in a single dose. Treatment dosing of amoxicillin is variable based on age and severity of infection. Cephalosporins can also be used for treatment and/or prophylaxis.

Antibiotic management of pediatric UTIs is always done with caution. Age-related dosing restrictions, comorbid conditions, and severity of infection must be considered before treatment is recommended. These issues also affect the decision of whether to use inpatient intravenous therapy versus outpatient oral management. Children who appear toxic and those younger than 2 months of age who have suspected pyelonephritis should receive intravenous treatment. Ampicillin and aminoglycoside (if there is no known drug allergy) are started until culture and sensitivity results are final. Fluoroquinolones have been approved by the Food and Drug Administration for the treatment of complicated UTIs in children. In children who present with a febrile UTI but do not appear toxic, 1 to 2 days of intramuscular ceftriaxone can provide coverage until culture results are final and appropriate oral therapy is determined.

The family should be educated on the signs and symptoms of a UTI at this appointment. They should be able to differentiate between a significant upper tract or kidney infection and lower tract symptoms or bladder infection. With a history of vesicoureteral reflux, at the first sign of infection, the child should be evaluated. The signs and symptoms of UTI should be revisited when discussing the x-ray evaluation with the family. If a urinalysis is positive, treatment should be started before culture results have been received to prevent the development of pyelonephritis. Vesicoureteral reflux should be evaluated by ultrasound and VCUG every 12 to 18 months. As long as the child has good overall renal growth, no evidence of scarring, no infections while on prophylaxis, and no worsening reflux, the child can be managed conservatively. If they have breakthrough infections or upper tract changes, alternate management would need to be considered. This would warrant a referral to a pediatric urologist. Other variables that might lead to surgical management are allergies to multiple antibiotics and poor compliance with medical management.

Antibiotic prophylaxis is appropriate for a child with a history of recurrent febrile infection until she has been evaluated fully. She is at risk for anatomical abnormalities and should be maintained on prophylaxis until her x-ray evaluation is complete.

Dysfunctional elimination must be addressed regardless of the results of her x-ray evaluation. She needs to be placed on a timed voiding regimen during the day. She is in the habit of holding her urine to the point of having urge incontinence. Often, these children have difficulty relaxing the external sphincter and do not take time to void to completion. This is complicated by constipation, which increases colonization of the intestinal flora and may create difficulty with voiding to completion.

You explain to the mother that her daughter’s dysfunctional elimination will be managed by placing her on a strict timed voiding schedule during the day, every 2 hours by the clock, whether she has the urge to urinate or not. You suggest using a simple behavioral modification chart with days of the week and times of the day for scheduled voiding, which can be created with stickers to recognize her cooperation with the plan.

There are rare cases in which children with dysfunctional elimination, UTI, and reflux have symptoms that persist or worsen, even with appropriate management. This outcome could indicate a neurologic abnormality, so evaluation of the lower spine by magnetic resonance imaging may need to be done. Other symptoms that can be associated with neurologic issues are chronic back and lower extremity pain, gait abnormalities, and stool incontinence. Physical evidence of bony abnormalities can sometimes be seen on plain radiographs, or as sacral dimples, gluteal asymmetry, lower spine discolorations, or a sacral hair patch.

The correct answer is F

Comment: Some people are at higher risk of getting a UTI. UTIs are more common in females because their urethras are shorter and closer to the rectum. This makes it easier for bacteria to enter the urinary tract. Changes in the vaginal bacterial flora, such as during menopause or the use of spermicides, can cause these bacterial changes. So can poor hygiene, for example in children who are toilet training and primary or secondary vesicoureteral reflux.

The correct answer is E

Comment: The differential includes acute cystitis, a more extensive UTI, vaginitis, and urethritis. Urethritis would most likely be caused by a sexually transmitted pathogen. There are no other symptoms that would point to a sexually transmitted disease, and the patient’s history does not suggest this alternative. Vaginitis is also a reasonable possibility, but the physical examination did not reveal any obvious symptoms of this type of infection. There are no indications of an upper UTI (e.g., fever, flank pain), so it would appear that the patient simply has yet another case of acute cystitis.

The correct answer is C

Comment: In women who present with one or more symptoms of UTI, the probability of infection is approximately 50%. Specific combinations of symptoms (e.g., dysuria and frequency without vaginal discharge or irritation) raise the probability of UTI to more than 90%, effectively ruling in the diagnosis based on history alone.

The correct answers are A, B, and C

Comment: The most appropriate tests would include urinalysis with microscopic evaluation of clean-catch urine for bacteria and pyuria, a urine culture, and a complete blood count with differential.

The correct answer is C

Comment: The results support a diagnosis of acute cystitis. Enterococci, group B streptococci, and some staphylococci are known to cause UTIs. The positive catalase test eliminates enterococci and Group B streptococci. The negative coagulase test eliminates Staphylococcus aureus . At present, the coagulase-negative Staphylococcus species that are most likely to cause cystitis in a young woman is Staphylococcus saprophyticus .

The correct answer is B

Comment: The method for obtaining urine for culture is a random collection taken at any time of day with no precautions regarding contamination. The sample may be dilute, isotonic, or hypertonic and may contain white cells, bacteria, and squamous epithelium as contaminants. In women, the specimen may contain vaginal contaminants such as trichomonads, yeast, and, during menses, red cells.

Early morning collection of the sample before ingestion of any fluid is usually hypertonic and reflects the ability of the kidney to concentrate urine during dehydration, which occurs overnight. If all fluid ingestion has been avoided since 6 p.m. the previous day, the specific gravity usually exceeds 1.022 in healthy individuals.

Clean-catch, midstream urine specimen is collected after cleansing the external urethral meatus.

A cotton sponge soaked with benzalkonium hydrochloride is useful and nonirritating for this purpose. A midstream urine is one in which the first half of the bladder urine is discarded and the collection vessel is introduced into the urinary stream to catch the last half. The first half of the stream serves to flush contaminating cells and microbes from the outer urethra before collection. This sounds easy, but it is not (try it yourself before criticizing the patient). It can be messy, which reduces compliance.

Catheterization of the bladder through the urethra is carried out only in special circumstances (i.e., in a comatose or confused patient). This procedure risks introducing infection and traumatizing the urethra and bladder, thus producing iatrogenic infection or hematuria.

When done under ideal conditions, suprapubic transabdominal needle aspiration of the bladder provides the purest sampling of bladder urine. This is a good method for infants and small children.

The correct answers are A, B, C, D, and E

Comment: Recurrence of UTI may be either a relapse (i.e., the reappearance of the original infection) or, far more commonly, reinfection, which is the occurrence of a new infection. Relapse is caused by the same organism that caused the original infection and usually occurs within 2 weeks following the completion of antibiotic therapy. The short time frame suggests that the causative organism has persisted in the urinary tract or nearby, possibly because of an anatomic problem such as a stone or obstruction. A subclinical kidney infection (pyelonephritis or renal abscess) is another possibility. This patient’s history does not support a diagnosis of relapse because the identity of the infectious agent changes from one incident to the next and the recurrences did not occur soon enough after completing antibiotic therapy. Reinfections can be caused by a different organism or by the same organism that caused the original infection. They can occur at any time after the original infection and do not imply an anatomical abnormality. It is not at all unusual for young women to experience a series of recurrent UTIs that are unrelated to anatomical abnormalities or other conditions. In fact, 10% of all women experience this problem at some point in their lives.

The correct answers are A and B

Comment: The major goal here is to interrupt the cycle of colonization of the introitus and infection of the bladder. Success is achieved with drugs such as trimethoprim-sulfamethoxazole or some quinolones, which reach high concentrations not only in urine but also in vaginal secretions. Treatment generally requires long-term prophylaxis (low dose), which may be administered either continuously or after intercourse (preferred). ^,

The correct answer is A

Comment: Neonatal jaundice is a common problem in infancy. It is seen in 60% of full-term and 80% of preterm newborns. Most cases are due to an increase in the direct fraction of bilirubin, whereas only 0.04% to 0.2% are cholestatic jaundice. Physiological hyperbilirubinemia is considered the most common cause of jaundice after the first day of life, accounting for 53.9% of cases. Among breast-fed infants, 15% experience some sort of jaundice for more than 3 weeks. However, only a few infants with neonatal jaundice are found to have pathological causes, including metabolic and endocrine diseases, underlying hemolytic causes, congenital deficiency of liver enzymes, and bacteremia or sepsis. The latter may cause increased direct fraction of bilirubin in infancy after first week of life, with UTI being the most common cause. Gram-negative organisms were isolated from most cases of sepsis-related jaundice, of which E. coli was the most common causative agent. Infants with structural abnormalities in the urinary tract are more susceptible to hyperbilirubinemia associated with UTI. These findings were especially related to hydronephrosis and vesicoureteral reflux, which are consistent with our case report. ^,

Some studies have found that hyperbilirubinemia could be the first and only manifestation of neonatal sepsis and UTI. As in our patient, this was the case for a 2-month-old neonate reported in Turkey in 2017. He presented with jaundice 1 week after birth, and urine culture was positive for K. pneumonia, but no other signs of sepsis or UTI, which is uncommon. However, his jaundice resolved completely after treating his UTI. Another case was reported in an 8-year-old girl who presented with jaundice and UTI from E. coli . Jaundice also resolved completely after treating the UTI.

Infants with UTI usually have an increased indirect fraction of bilirubin. ^, This might be due to hemolysin toxins secreted by certain strains of gram-negative bacteria and increased red blood cell fragility, which eventually causes hemolysis and unconjugated hyperbilirubinemia.

However, in our case and the other case reports mentioned previously, there was an increase in the direct fraction of bilirubin, which is defined as a conjugated bilirubin concentration of more than 2 mg/dL or more than 20% of total bilirubin. Several mechanisms have been suggested to explain cholestatic jaundice in a setting of UTI. Endotoxins secreted by gram-negative organisms are thought to be the main cause of UTI-related hyperbilirubinemia. A marked decrease in multidrug resistance–associated protein 2, an ATP-dependent transporter involved in the bile- and salt-independent bile export system, under oxidative stress caused by lipopolysaccharide (LPS) endotoxins from the bacterial outer membrane, has been reported. ^– This causes bile stasis because of impaired excretion and indirectly damages hepatocytes.

Another suggested mechanism is direct hepatocellular damage caused by the invasion of gram-negative bacteria during an episode of bacteremia. However, the latter mechanism is not reliable because cholestatic syndrome was documented even in the absence of bacteremia. Moreover, LPS released in the bloodstream from gram-negative organisms causes suppression of the inner circular muscles of the intestinal wall. This is thought to be the cause of sepsis-associated ileus and could explain constipation in our case. ^,

The correct answer is A

Comment: S. epidermidis commonly causes infections associated with indwelling central venous catheters, cerebrospinal fluid shunts, prosthetic heart valves, and peritoneal dialysis catheters. When S. epidermidis is isolated from blood or body fluids in patients without predisposing factors, it is often considered a contaminant. Urinary tract infections caused by S. epidermidis are often associated with instrumentation of the urinary tract in a hospital setting, including neonates in the neonatal intensive care unit.

Our patient was a previously healthy infant who presented with persistent fever and had elevated WBC and C-reactive protein. Urinalysis showed 105 CFU/mL of S. epidermidis on two separate occasions. Imaging studies revealed a smaller right kidney with evidence of cortical thinning and right-sided vesicoureteral reflux. ^–

Hall and Snitzer described two children (a 6-year-old and a 7-year-old) who presented with fever and shaking chills. Urine culture from each of these patients grew S. epidermidis on two occasions. Imaging studies identified vesicoureteral reflux in both cases. It is noteworthy that in both of the aforementioned reports of S. epidermidis UTI, there was a lack of significant pyuria. ^, This was also noted in our patient where urine microscopy showed only 5 to 10 WBC/hpf. This finding and the absence of urine nitrites, which are predominantly produced by gram-negative bacteria, indicate that urine dip and microscopy are less helpful in diagnosing urinary tract infections from S. epidermidis . Previous studies have suggested that in view of the tendency of Staphylococcus to form clusters, a count of 103 CFU/mL may be a significant marker for UTI. Urinary radiographic imaging in the previous two reports revealed underlying abnormalities in all three cases (vesicoureteral reflux). Our patient also has severe bilateral reflux.

The correct answer is C

Comment: Our patient symptoms included acute dysuria, suprapubic pain, frequent urination, urgent urination, urge incontinence, and macrohematuria in the absence of pyuria or urinary tract infection. His urinary symptoms disappeared 3 days after the start of antibiotic, and blood eosinophils were normal. The clinical manifestations in the case were consistent with EC. Biopsy of the lesions through the urethra revealed infiltration of blood vessels and eosinophils into the muscular layer, accompanied by focal muscle necrosis.

EC is an uncommon primary inflammatory disorder of the bladder with uncertain etiology. The incidence of EC in male adults is increased compared with female adults. Similarly, the incidence of EC in male children is increased compared with females; the average age of onset in children is 6 years. The exact cause of EC remains unclear; however, certain studies have suggested that anaphylaxis may be a trigger. Allergens may include food, dust mites, pollen, condom antigens, iodine, and anesthetic creams. Asthma and celiac disease are also associated with EC. In the present study, the patient in case 1 was sensitive to Dermatophagoides pteronyssinus and Dermatophagoides culinae , whereas the patient in case 2 had no specific allergies. The pathogenesis of EC involves immunoglobulin E–mediated eosinophil activation, with subsequent mast cell degranulation and muscle damage. Patients with EC often exhibit a series of urinary symptoms, including frequent urination, hematuria, suprapubic pain, dysuria, and daytime and nocturnal enuresis; children with EC may have a clear suprapubic mass. The clinical manifestations in the cases presented in the present study were consistent with EC; however, the clinical manifestations of EC are often varied and may be easily confused with nonspecific cystitis. Children with suprapubic masses should also be differentiated from those with malignant bladder tumors. EC is a rare condition that can mimic invasive bladder cancer symptoms. EC diagnosis may be considered if a bladder tumor is associated with eosinophilia. The eosinophil count in the blood was significantly increased in each of the two cases, and a bone marrow biopsy revealed increased eosinophils. In a number of patients with EC, peripheral blood eosinophilia occurs without reaching the level of eosinophilia syndrome. Patient 2 only received treatment by antiinflammatory and cetirizine hydrochloride without steroid therapy. During hospitalization, the eosinophils were found to be decreased in a routine blood test, and the patient’s symptoms gradually improved. It has previously been suggested that EC may also present a self-healing trend. In the present study, patient 1 presented with similar symptoms 3 years earlier; an US revealed thickening of the bladder wall, and following 3 days of antiinflammatory treatment, the symptoms disappeared. In addition, patient 1 was allergen-positive. The authors hypothesize that the onset of the disease in case 1 was associated with allergens, and that with the elimination of inflammatory mediators, symptoms may disappear. It has previously been reported that urine cultures are positive in EC patients. However, the urine cultures in each of the cases presented herein were negative. Eosinophils are rarely observed in urine sediments and are rapidly degraded or rarely detached from the mucosa. Certain EC patients have hematuria symptoms. If an imaging examination reveals bladder wall thickening, which is similar to mass infiltration, a tumor is suggested. Cystoscopy results usually suggest bladder rhabdomyosarcoma. Intense inflammatory changes, including congestion and edema of the bladder wall, may result in intense inflammatory changes in the bladder wall, and associated with this, lesion may produce excrescences, which resemble vesical rhabdomyosarcoma. Because EC is very rare in children, there are no ideal guidelines for its treatment and follow-up, and treatment is typically based on experience. First-line treatments typically involve the removal of any suspected allergens, followed by the use of antihistamines and corticosteroids. It has been reported that corticosteroids may accelerate the remission of symptoms and stabilize lysosomal membranes because of their antiinflammatory effects. For refractory cases, cyclosporine A is administered orally for 8 months. For children with peripheral blood eosinophilia, montelukast sodium is used. Researchers have also tried intravesical instillation of dimethyl sulfoxide twice per week. EC in children is normally benign and self-limiting; however, it may still develop into bladder fibrosis and secondary urinary tract obstruction. The diagnosis and treatment of EC depend on clinical suspicions and histopathological examination.

In conclusion, EC in children is similar to a tumor; however, it has its own characteristics. Although it is a rare disease, it should be considered when urinary tract symptoms and bladder wall thickening are observed in children. Bladder biopsy and histopathological evaluation are important for the diagnosis of EC and allow for the selection of an appropriate treatment.