A 9-month-old girl is brought to the office due to fever and poor feeding over the past day. During the last few days, the patient has become more fussy than usual and developed a fever yesterday. Today, she has not finished her formula bottles, and her stools have been slightly loose but nonbloody. Temperature is 39 C (102.2 F), pulse is 142/min, and respirations are 36/min. The fontanelle is open, soft, and flat. Tympanic membranes are clear bilaterally. Cardiac examination shows normal heart sounds; there are no murmurs, rubs, or gallops. The lungs are clear to auscultation bilaterally. The abdomen is soft and bowel sounds are present. The skin has no rashes or erythema. Urinalysis reveals positive nitrites and leukocyte esterase. Which of the following is the most appropriate pharmacotherapy for this patient?

Question

A 9-month-old girl is brought to the office due to fever and poor feeding over the past day.  During the last few days, the patient has become more fussy than usual and developed a fever yesterday.  Today, she has not finished her formula bottles, and her stools have been slightly loose but nonbloody.  Temperature is 39 C (102.2 F), pulse is 142/min, and respirations are 36/min.  The fontanelle is open, soft, and flat.  Tympanic membranes are clear bilaterally.  Cardiac examination shows normal heart sounds; there are no murmurs, rubs, or gallops.  The lungs are clear to auscultation bilaterally.  The abdomen is soft and bowel sounds are present.  The skin has no rashes or erythema.  Urinalysis reveals positive nitrites and leukocyte esterase.  Which of the following is the most appropriate pharmacotherapy for this patient?

Quizplus · Accepted Answer

11ec25c8_d732_2fe8_bc81_cfb604bbafb6_MD0003_00 Urinary tract infections (UTIs) are common in children, particularly in girls and uncircumcised boys during infancy. Escherichia coli is the most common etiology, followed by other gram-negative bacteria (eg, Klebsiella, Proteus). UTIs often present with vague symptoms in infants and should be suspected in a child with fever (especially temperature ≥39 C [102.2 F]), fussiness, and poor feeding, as seen in this patient. Positive nitrites (specific for Enterobacteriaceae) and leukocyte esterase (produced by white blood cells) on urinalysis are highly suggestive of a UTI. Bacteriuria on urine culture confirms the diagnosis. When a UTI is suspected based on clinical presentation and urinalysis, empiric antibiotics are recommended because a delay in therapy increases the risk of renal complications (eg, scarring, hypertension). To cover the most common pathogens, children are typically treated with a third-generation cephalosporin, such as cefixime. Local patterns of bacterial resistance may affect the initial choice; there are increasing rates of resistance among E coli to trimethoprim-sulfamethoxazole, first-generation cephlosporins, and amoxicillin-clavulanate. Antibiotics may be modified based on the urine culture results. (Choice A) Azithromycin is a macrolide used to treat upper airway infections and sexually transmitted infections caused by Chlamydia; it is not typically used for UTIs because it does not adequately cover coliform organisms. (Choice C) Although fluoroquinolones treat E coli, use is limited in children due to the risk of cartilage damage. Ciprofloxacin is reserved for treatment of UTIs caused by Pseudomonas aeruginosa, which typically occur in patients with an indwelling catheter (not seen in this patient). (Choice D) Clindamycin has activity against gram-positive bacteria (including methicillin-resistant Staphylococcus aureus) and anaerobes but not aerobic gram-negative bacteria. S aureus is a rare cause of UTI that would not result in positive nitrites on urinalysis. (Choice E) Penicillin is the treatment of choice for group A streptococcal infections but does not have gram-negative activity. Educational objective: Urinary tract infections are most commonly caused by gram-negative bacteria (eg, Escherichia coli) and can present with fever and fussiness in an infant. The presence of nitrites and leukocyte esterase on urinalysis is characteristic. Empiric therapy with a third-generation cephalosporin is recommended. References: Urinary tract infection: clinical practice guideline for the diagnosis and management of the initial UTI in febrile infants and children 2 to 24 months. (http://www.ncbi.nlm.nih.gov/pubmed/21873693)

A 9-Month-Old Girl Is Brought to the Office Due to Fever