1. What is infantile roseola? Roseola infantum, also known as erythema infantum, is a common infectious disease in infants and young children. It usually occurs in babies between 3 and 5 months old, but can occur anytime from two weeks to six months after birth. The disease usually resolves on its own, but care is needed to protect and care for your baby during this time. 2. The initial symptoms of infantile roseola include high fever, runny nose, conjunctival congestion and other symptoms of respiratory infection. Red patches on the skin then appear, usually starting on the face and spreading to other parts of the body. These spots can