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Rigors in febrile children may be associated with a higher incidence of serious bacterial infection.

Three Part Question

In [febrile children presenting to the Emergency department] are [rigors] suggestive of [serious bacterial infection]?

Clinical Scenario

An 18 month old child presents to the A&E department with a temperature of 39 degrees celsius. The child's temperature falls to 37.2 degrees celsius following paracetamol. The child has an inflammed pharynx on examination, and when a history is taken, the child's mother reports that the child has experienced rigors in the last 24 hours. There has been no foreign travel. The mother asks if the rigor makes bacterial infection more likely?

Search Strategy

Cochrane; CINAHL; Medline; Embase
Cochrane library - "Rigors"
Medline -"Rigors" OR "Rigor" Limits "All child: 0-18 years" "Humans"
CINAHL - "Rigor AND (Febrile OR Pyrexia)", 1980 to 2007/02
Embase -"Rigor AND (Febrile OR pyrexia)", 1980 to 2007/02

Search Outcome

Cochrane Library - No relevant papers
Medline - 494 hits, 1 relevant
CINAHL - 1 hits, 0 relevant
EMBASE - 108 hits, same single relevant paper as found on medline

Relevant Paper(s)

Author, date and country Patient group Study type (level of evidence) Outcomes Key results Study Weaknesses
Tal, Y. Even, L. Kugelman, A. Hardoff, D. Srugo, I. Jaffe, M.
Children admitted to paediatric ward with febrile illness, 100 children who had experienced rigors prior to admission, 334 children who had not experienced rigors.Retrospective Cohort StudyProven bacterial infection (positive blood, urine or stool culture).15% rigor group had positive culture vs 6% of non-rigor group (Sens = 0.71, Spec = 0.52, PPV = 0.15, NPV = 0.94, LR = 1.47)All children unwell enough to require hospitilization. Allocation to group on basis of history of rigors, not observed rigors by clinician. No blinding for either outcome. Diagnosis of presumed bacterial infection in absence of positive culture was in part subjective.
Diagnosis of presumed bacterial infection67% of rigor group presumed bacterial infection vs 50% of non-rigor (Sens = 0.57, Spec = 0.6, PPV = 0.67, NPV = 0.5, LR = 1.42)


Only one paper was found examining the significance of rigors in febrile children. Children were already judged ill enough to require hospital admission, and so may not be representative of patients presenting directly to the Emergency Department. The diagnosis of presumed bacterial infection in this paper was made on clinical grounds in some children in the absence of positive cultures. All children had blood, urine and stool cultures. No data is given in the paper as to how many children under went lumbar puncture, nor are the results of CSF cultures given. Lumbar puncture was only performed when felt to be clinically indicated. Throat swabs were not taken.

Clinical Bottom Line

Children admitted to hospital with a febrile illness but no rigors are less likely to have positive bacterial cultures than those who have rigors. but, they may still have a clinical diagnosis of a bacterial infection.


  1. Tal, Y. Even, L. Kugelman, A. Hardoff, D. Srugo, I. Jaffe, M. The clinical significance of rigors in febrile children. European Journal of Pediatrics. 1997, 156(6):457-9.