Fever and Rash in Children

Immediate Life-Threatening Considerations

Meningococcemia and Rocky Mountain Spotted Fever (RMSF) can present with fever and rash in children and can be rapidly fatal, according to the Centers for Disease Control and Prevention (CDC) 1, 2
Meningococcemia cannot be reliably distinguished from tick-borne rickettsial disease on clinical grounds alone, so consider administering intramuscular ceftriaxone pending blood culture results if the child appears ill, as recommended by the CDC 3
RMSF can have a rapid course with 50% of deaths occurring within 9 days of illness onset, and early serology is typically negative, as reported by the CDC 1, 2
If the rash becomes petechial or purpuric, or if the child develops hypotension, altered mental status, or respiratory distress, this is a medical emergency requiring immediate hospitalization, according to the CDC 1

Human herpesvirus 6 (roseola infantum) typically presents with 3-4 days of high fever followed by rash as fever resolves, as described by the CDC 1
Enteroviruses can cause fever with vesicular rash, according to the CDC 1, 2

Location of blisters: Palms and soles involvement suggests RMSF or viral exanthem; diaper area alone suggests irritant dermatitis or candidiasis, as noted by the CDC 1
Type of lesions: Flaccid blisters suggest SSSS; tense blisters suggest other causes; target lesions suggest Stevens-Johnson Syndrome, as described by the British Journal of Dermatology 4
Mucous membrane involvement: Oral, conjunctival, or genital erosions suggest Stevens-Johnson Syndrome or other serious conditions, according to the British Journal of Dermatology 4
Petechiae or purpura: Suggests meningococcemia, RMSF, or other serious bacterial infection, as reported by the CDC 1

Obtain complete blood count with differential, C-reactive protein, comprehensive metabolic panel, as recommended by Praxis Medical Insights 5
Blood culture before antibiotics, as suggested by the CDC 3 and the Annals of Emergency Medicine 6
Urinalysis and urine culture (urinary tract infections cause >90% of serious bacterial illness in this age group), according to the Annals of Emergency Medicine 6
If tick exposure possible or geographic risk: acute serology for R. rickettsii, as recommended by the CDC 3, 1

Empiric doxycycline treatment is indicated regardless of age, including children <8 years, for suspected RMSF, as recommended by Praxis Medical Insights 5
Do not wait for serologic confirmation, as early serology is typically negative, according to the CDC 1, 2
Broad-spectrum antimicrobials including penicillins, cephalosporins, and erythromycin are NOT effective against rickettsiae, as reported by the CDC 1, 2

Do not assume a benign diagnosis based solely on the "diaper rash" appearance - many serious conditions can present with rash in the diaper area, as noted by the CDC
Do not be dissuaded from diagnosing RMSF by absence of reported tick bite - up to 40% of RMSF patients report no tick bite history, according to the CDC 3, 2
Do not rely on response to antipyretics to exclude serious bacterial infection - fever response does not reliably predict bacterial versus viral etiology, as reported by the Annals of Emergency Medicine 7
Do not wait for positive serology to treat suspected RMSF - antibodies are not detectable in the first week of illness, according to the CDC 1, 2
Do not assume geographic safety from RMSF - it should be considered endemic throughout the contiguous United States, as reported by the CDC 1, 2

Admit to hospital if: Child appears toxic or has signs of sepsis, as recommended by the Annals of Emergency Medicine 6
Admit to hospital if: Extensive blistering suggesting SSSS, according to the British Journal of Dermatology 4
Admit to hospital if: Mucosal involvement suggesting Stevens-Johnson Syndrome, as reported by the British Journal of Dermatology 4
Admit to hospital if: Suspected meningococcemia or RMSF with systemic symptoms, according to the CDC 3
Admit to hospital if: Age <28 days with any fever, as recommended by the Annals of Emergency Medicine 7