Does Vicks Cause Body Rashes?

My son has had a low grade fever going on 10 days now ( it only Drainage , coughs, runny nose , coughing spells that cause him to vomit . Took him to urgent and they told me he should be better in a couple days and told me to give him a low dose zrytec.6 days later and we are still having problems. Is the fever returning for that many days something to worry about ??? Also , can Vicks cause a rash where I have been putting it on him for a week now? Do I need to take him back to the doctor ? ( I will add my daughter had strep last week but urgent care did not test my son for strep , I think that was odd but he didn t have a fever when I took him in so that may be why they out weighed it.)