- determine clues to etiology.
- Is there a community outbreak? Any ill family members or close contacts?
- Consider opportunistic etiologies in an immunodeficient child.
- An incompletely immunized child may be at risk for a vaccine-preventable disease such as varicella or measles.
- Timing of the rash may suggest etiology (e.g., several days of fever precedes rash in RMSF and roseola).
- Elicit rash distribution and progression. Scarlet fever rash begins on the face and spreads caudally. The lesions of RMSF begin on the distal extremities, involve palmar and solar surfaces, and spread centripetally. Morphology is also important. A maculopapular rash that becomes petechial or purpuric within several hours suggests meningococcemia.
- Mental status changes suggest a life-threatening bacterial infection, such as meningococcemia, RMSF, or toxic shock syndrome