Hi
Fever with rash is caused by variety of reasons [measles, chicken pox, roseola,scarlet rash,
erythema infectiosum,
Kawasaki disease, CMV, enterovirus, EBV, Hemorrhagic fever, VZV, Dengue,
thrombocytopenia etc]. The size, shape, level, order of appearance etc are important characteristics to distinguish rashes and reach the possible cause. It is very much important to get your child examined by
pediatrician and start the treatment accordingly.Some of these require medical intervention and hospitalization.
Severe loose stools - is another symptom to concern. You baby may be getting dehydrated and losing electrolytes. These cause lethargy.
Severe dehydration is a predominant killer in children. If the situation goes on, he may need to be given intravenous fluids. I am worried about his hydration status.
Please don't wait. Get him examined by doctor as soon as possible. Meanwhile, give him sufficient oral fluid, ORS, juice etc to prevent dehydration.