itching on neck&face,don't know from what? possible drug interaction,what to do? Who should I see?

Question

In July went to a car show came home with red on face,neck,arms,ankles and spots on top of feet. It itched without any relief. Every time I went out which was every weekend to the festivals I would get more red and more itching. My doctor told me to go to a dermatologist by it has cleared up now that it isn't hot and sunny any more. So what could a drmatologist do at this point? We did change one medication that I was taking that my have caused this. What can a dermatoloist do now? I have now a virus and been coughing and have taken some otc meds for it. Now I have this itching on my neck and some on my face, no rash just itching. Is this a reaction to something I've taken or an interaction between  my regualr meds and the otc meds? Is this also something that I sould see a drmatologist for? Please, Please help me I am tire of all this!