Clinical and laboratory features, hospital course, and outcome of Rocky Mountain spotted fever in children

J Pediatr. 2007 Feb;150(2):180-4, 184.e1. doi: 10.1016/j.jpeds.2006.11.023.


Objectives: To describe the clinical characteristics and course of children with laboratory-diagnosed Rocky Mountain spotted fever (RMSF) and to identify clinical findings independently associated with adverse outcomes of death or discharge with neurologic deficits.

Study design: Retrospective chart review of 92 patients at six institutions in the southeastern and southcentral United States from 1990 to 2002. Statistical analyses used descriptive statistics and multiple logistic regression.

Results: Children with RMSF presented to study institutions after a median of 6 days of symptoms, which most commonly included fever (98%), rash (97%), nausea and/or vomiting (73%), and headache (61%); no other symptom or sign was present in >50% of children. Only 49% reported antecedent tick bites. Platelet counts were <150,000/mm3 in 59% of children, and serum sodium concentrations were <135 mEq/dL in 52%. Although 86% sought medical care before admission, only 4 patients received anti-rickettsial therapy during this time. Three patients died, and 13 survivors had neurologic deficits at discharge. Coma and need for inotropic support and intravenous fluid boluses were independently associated with adverse outcomes.

Conclusions: Children with RMSF generally present with fever and rash. Delays in diagnosis and initiation of appropriate therapy are unacceptably common. Prognosis is guarded in those with hemodynamic instability or neurologic compromise at initiation of therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Distribution
  • Blood Chemical Analysis
  • Child
  • Child, Preschool
  • Confidence Intervals
  • Female
  • Follow-Up Studies
  • Hospitalization / statistics & numerical data
  • Humans
  • Incidence
  • Male
  • Odds Ratio
  • Rickettsia rickettsii / isolation & purification*
  • Risk Assessment
  • Rocky Mountain Spotted Fever / diagnosis*
  • Rocky Mountain Spotted Fever / epidemiology*
  • Rocky Mountain Spotted Fever / physiopathology
  • Severity of Illness Index
  • Sex Distribution
  • Survival Rate
  • United States / epidemiology