Skin rash in children with fever could be due to multiple reasons like - Chicken pox, measles, roseola, erythema infectiosum
, Kawasaki disease
, CMV, enterovirus, EBV, Hemorrhagic fever, VZV, Dengue, thrombocytopenia
etc. Some of these conditions needs urgent treatment.
Clinical examination of your child is very much necessary as size, shape, level, order of appearance etc are important characteristics to distinguish rashes and reach the possible cause.
Please go to pediatrician
and get the diagnosis and proper treatment.