Roseola is a mild viral illness of childhood. It is characterized by high fever that typically comes on suddenly and lasts for three to five days. Other symptoms of roseola are mild nasal congestion, eye redness, and a rash that appears after the fever has resolved. The rash is usually pink in color and consists of tiny flat or slightly raised dots. Nonspecific symptoms can occur in ill infants and children. These can include fatigue, poor feeding, diarrhea, runny nose, and irritability.

Source: http://www.rxlist.com