What Causes Itchiness And Slight Burning Sensation Around The Anus?

I am experiencing itchiness, discomfort, and slight burning sensation around my anus, do you have any ideas what it could be and how to treat it please? It has been like this for just under a week, but because of the area in which it is, i am embarrassed to go to the doctor about it. I am English but live in Thailand so most medication here can be bought over the counter. Please advise?