Hi My Son Has Had A Fever The Last 3

Hi

My son has had a fever the last 3 days with no other symptoms.He has mottled skin that gets worse when his temp goes up.My doctor said to come back in a few days but I am worried its something more serious.He is happy when the fever reducer drugs kick in.He doesn't have much of an appetite but is eating a drinking.He isn't nursing as much as he usually does.

Any help

Thanks

Laura