Treatment for Fever and Rash in Children

Immediate Clinical Assessment

The American Academy of Pediatrics and the Centers for Disease Control and Prevention recommend starting empiric doxycycline immediately if Rocky Mountain Spotted Fever (RMSF) is suspected, as delay in treatment significantly increases mortality risk, particularly in young children who can deteriorate rapidly within days 1, 2
The presence of fever with rash involving face, trunk, and extremities in a 2-year-old requires urgent evaluation for life-threatening conditions, such as RMSF, which can have a mortality rate of up to 50% if left untreated 2
The Centers for Disease Control and Prevention recommend that if the rash appears 2-4 days after fever onset and involves the extremities, doxycycline should be started immediately without waiting for confirmatory testing, as 50% of RMSF deaths occur within 9 days of illness onset 2
Petechial progression, which indicates advanced disease, requires immediate hospitalization and aggressive treatment, with a mortality rate of up to 20% if left untreated 3, 4
Up to 40% of RMSF patients report no tick bite, so absence of this history should not exclude the diagnosis, and the Centers for Disease Control and Prevention recommend considering RMSF in the differential diagnosis of any patient with fever and rash 5

The American Academy of Pediatrics recommends assessing for RMSF characteristics, including fever with sudden onset, severe headache, myalgias, and rash beginning on ankles/wrists/forearms spreading centrally, and starting doxycycline 2.2 mg/kg/dose twice daily immediately if suspected 1, 3
The Centers for Disease Control and Prevention recommend that if RMSF is excluded, evaluating for Kawasaki Disease, which requires immediate treatment with IVIG 2 g/kg as single infusion plus high-dose aspirin 80-100 mg/kg/day divided every 6 hours within 10 days of fever onset to prevent coronary artery aneurysms 7, 8

The American Academy of Pediatrics and the Centers for Disease Control and Prevention recommend never delaying doxycycline for RMSF, as penicillins, cephalosporins, aminoglycosides, erythromycin, and sulfa-containing drugs are completely ineffective against rickettsiae, and the mortality rate can be up to 50% if left untreated 2
The Centers for Disease Control and Prevention recommend not waiting for serologic confirmation, as IgM and IgG antibodies are not detectable before the second week of illness, making early serology useless for acute management, and the mortality rate can be up to 20% if left untreated 2
The American Academy of Pediatrics recommends not excluding RMSF based on geography, as RMSF should be considered endemic throughout the contiguous United States, and the mortality rate can be up to 50% if left untreated 2

The Centers for Disease Control and Prevention recommend doxycycline 2.2 mg/kg/dose orally or IV twice daily for 5-7 days (or at least 3 days after fever resolves) for confirmed/suspected RMSF, with a mortality rate of up to 50% if left untreated 1
The American Heart Association recommends IVIG 2 g/kg as single infusion over 10-12 hours, and aspirin 80-100 mg/kg/day divided every 6 hours until afebrile for 48-72 hours, then reduce to low-dose 3-5 mg/kg/day once daily for 6-8 weeks for Kawasaki Disease, with a mortality rate of up to 25% if left untreated 7, 8

The American Academy of Pediatrics and the Centers for Disease Control and Prevention recommend complete blood count, hepatic transaminases, and inflammatory markers, such as ESR and CRP, to support RMSF or Kawasaki disease diagnosis, and to guide treatment decisions 1, 2, 9
The Centers for Disease Control and Prevention recommend not delaying treatment for test results, as both RMSF and Kawasaki disease require immediate empiric treatment based on clinical suspicion, and the mortality rate can be up to 50% if left untreated 1, 7