A 3-month-old girl is brought to the clinic by her father due to fever and fussiness. A fever developed in the patient 2 days ago, and she has been receiving scheduled acetaminophen. The fever initially improved after medication administration but returned several hours later. Now, the patient does not want to feed and is not finishing her bottles but has had no vomiting. She has no rhinorrhea, cough, or congestion. The patient was born at term and had no complications. She has intermittent constipation for which she takes prune juice. Immunizations are up to date. Temperature is 39.4 C (102.9 F) and pulse is 160/min. Examination shows a tired-appearing girl. The fontanel is open and flat. Tympanic membranes are clear with normal bony landmarks. There are no exudates in the posterior oropharynx. The lungs are clear to auscultation bilaterally. The abdomen is soft and bowel sounds are present, but the girl cries during palpation of the lower abdomen. Which of the following is the best next step in management of this patient?

Question

A 3-month-old girl is brought to the clinic by her father due to fever and fussiness.  A fever developed in the patient 2 days ago, and she has been receiving scheduled acetaminophen.  The fever initially improved after medication administration but returned several hours later.  Now, the patient does not want to feed and is not finishing her bottles but has had no vomiting.  She has no rhinorrhea, cough, or congestion.  The patient was born at term and had no complications.  She has intermittent constipation for which she takes prune juice.  Immunizations are up to date.  Temperature is 39.4 C (102.9 F) and pulse is 160/min.  Examination shows a tired-appearing girl.  The fontanel is open and flat.  Tympanic membranes are clear with normal bony landmarks.  There are no exudates in the posterior oropharynx.  The lungs are clear to auscultation bilaterally.  The abdomen is soft and bowel sounds are present, but the girl cries during palpation of the lower abdomen.  Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

11ec25c8_d731_bab7_bc81_b3ea83ab9ac0_MD0003_00 Urinary tract infection (UTI) is the most common bacterial infection in febrile infants and should be considered in any young child with fever and no source. Girls and uncircumcised boys are at increased risk, and constipation is a predisposing factor. The presentation in infants is typically nonspecific and can include fever, fussiness, poor feeding, abdominal discomfort, and decreased urine output. Older children and adolescents may have dysuria, urgency, frequency, and localized suprapubic and/or flank pain. This infant has a fever ≥39 C (102.2 F) with no identifiable infection (eg, acute otitis media, bronchiolitis) on examination. She has some lower abdominal discomfort to palpation. The next step is to evaluate for an occult UTI with urinalysis and urine culture. In patients who are not toilet trained, straight catheterization is preferred for obtaining a sterile urine sample. Pyuria (ie, white blood cells) and bacteriuria (≥50,000 colony-forming units/mL from a catheterized sample) confirm the diagnosis. Treatment is with antibiotics to prevent pyelonephritis and renal scarring. (Choice A) Abdominal x-ray can detect increased stool. However, constipation alone would not explain this patient's fever. (Choice B) Abdominal ultrasonography assesses renal disease and is indicated in children age <2 with their first febrile UTI. However, the priority in this patient is to obtain a urinalysis and urine culture, followed by antibiotics. (Choice C) Noncontrast abdominal CT scan is the gold standard for diagnosing nephrolithiasis, which can present with abdominal pain. This patient's fever and young age make UTI more likely. (Choice D) Lumbar puncture is performed to evaluate for meningitis in all febrile neonates age <28 days and may be considered in febrile infants age <29-60 days. In contrast, this child is age 3 months and does not show signs of meningitis (eg, lethargy, vomiting, bulging fontanel). Educational objective: Urinary tract infection should be suspected in an infant with fever ≥39 C (102.2 F) with no identifiable source because presentation can be nonspecific (eg, fussiness, poor feeding). Urinalysis and urine culture are the first steps in evaluation. 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 3-Month-Old Girl Is Brought to the Clinic by Her