OK If I were you I would go to the doctor and get it checked out. It could be somthing else completly innocent. Some of the symptoms that you are describing sound like it could be what you think it is. If you don't get it checked out evey time you get something as small as a bug bite you'll get worried. You don't want to live that way. It is just better to know.
When I first noticed some signs I ignored them. Always saying to myself well if I notice it again then I'll get checked out. Then I had a really bad outbreak and I knew that it could not go uncheked any longer. Unfortunatly my fears were confirmed.
To prevent spreding it to other parts I think that the best method is just washing your hands. I feel like I wash mine compulsively now. Also try to aviod putting your hands in your mouth or eyes.
To remain on the positive side just tell yourself (if you do have it)that in all honesty it is just a skin rash. It dosn't make you crippled, def, or blind.
I hope I helped a little. I am fairly new to this myself, maybe there will be other great responses and I can learn something too. Good luck!