Difficult...: It is difficult to tell without looking at it but the fact that it started as a blister and now has developed a crust seems to be associated with a cold sore. Usually should go away in a few days. If it persists then you should get it seen by your doctor.
Answered 1/7/2015
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A doctor has provided 1 answer
A doctor has provided 1 answer
A doctor has provided 1 answer
A doctor has provided 1 answer
8 doctors weighed in across 2 answers
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