What test can i take to determine whether i have rosacea?

None: It is diagnosed by exam only. There is no test.

Physical exam: Rosacea is a common, chronic, acne-like skin condition that affects adults, and its symptoms tend to come and go. Rosacea triggers include alcohol, hot or spicy foods, emotional stress, and increased temperature or exposure to sun. It can be a troubling condition, but there are effective medical treatments available.