Rash on chest area; only seen since a hour ago and few times through out the last couple of days. what could it be? allergic reaction to something?

Could be: Are they itchy? It is likely be allergy reaction. Sometimes could be hive. Check with your doctor is a good way.

Possible: Tough to diagnose rashes over the computer. Contact dermatitis reactions usually occur where you came in contact with something, so if only on the chest, did you get a new necklace for example? Nickle dermatitis from jewelry is common. Some bacteria can cause a rash such as scarlatina caused by a strep infection, etc. If it persists, see a dr. For an evaluation of the area. Best wishes.

Many answers: It may be from a drug reactions or just a viral infection. In the former, the rash would usually but not always subside in about a week after the drug has been discontinued, in the latter about 7 to 10 days. If the problem persists, see your doctor.