title: The crying infant: diagnostic testing and frequency of serious underlying disease.
abstract: OBJECTIVE
  To determine the proportion of children evaluated in an emergency department because of crying who have a serious underlying etiology. Secondary outcomes included the individual contributions of history, physical examination, and laboratory investigations in determining a diagnosis.
  
  
  METHODS
  We performed a retrospective review of all afebrile patients <1 year of age who presented with a chief complaint of crying, irritability, screaming, colic, or fussiness. All children with a serious underlying illness were identified by using a priori defined criteria. Chart review was conducted to determine if history, physical examination, or investigation data contributed to establishing the child's diagnosis.
  
  
  RESULTS
  Enrollment criteria were met by 237 patients, representing 0.6% of all visits. A total of 12 (5.1%) children had serious underlying etiologies with urinary tract infections being most prevalent (n = 3). Two (16.7%) of the serious diagnoses were only made on revisit. Of the 574 tests performed, 81 (14.1%) were positive. However, only 8 (1.4%) diagnoses were assigned on the basis of a positive investigation. History and/or examination suggested an etiology in 66.3% of cases. Unwell appearance was associated with serious etiologies. In only 2 (0.8%) children did investigations in the absence of a suggestive clinical picture contribute to the diagnosis. Both of these children were <4 months of age and had urinary tract infections. Among children <1 month of age, the positive rate of urine cultures performed was 10%. Ocular fluorescein staining and rectal examination with occult blood testing were performed infrequently, and results were negative in all cases. Successful follow-up was completed with 60% of caregivers, and no missed diagnoses were found.
  
  
  CONCLUSIONS
  History and physical examination remains the cornerstone of the evaluation of the crying infant and should drive investigation selection. Afebrile infants in the first few months of life should undergo urine evaluation. Other investigations should be performed on the basis of clinical findings.
authors.affiliation: Hospital for Sick Children, Division of Pediatric Emergency Medicine, 555 University Ave, Toronto, Ontario, Canada. stephen.freedman@sickkids.ca
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Freedman
authors.forename: Nesrin
authors.initials: N
authors.lastname: Al-Harthy
authors.forename: Jennifer
authors.initials: J
authors.lastname: Thull-Freedman
mesh_terms: D003085:Colic / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D016638:Critical Illness; D003430:Cross-Sectional Studies; D003448:Crying; D003937:Diagnosis, Differential; D003955:Diagnostic Tests, Routine; D004636:Emergency Service, Hospital; D004927:Escherichia coli Infections / Q000175:diagnosis / Q000453:epidemiology; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008487:Medical History Taking; D009864:Ontario; D010808:Physical Examination; D014552:Urinary Tract Infections / Q000175:diagnosis / Q000453:epidemiology