However, fever in the presence of irritability, hypotension, a septic appearance, and a petechial or macular rash may point to meningococcemia, a medical emergency. Allergic Reaction. Swelling of ...

It has an incubation period of approximately 10–12 days, and clinical disease begins with symptoms of fever, conjunctivitis ... nonpruritic macular rash, predominantly on the neck and trunk.

Rash After Fever in Roseola Roseola usually causes a high fever that lasts about three to five days. The fever can reach temperatures as high as 103 to 105 degrees.