Cold Sores Patient Guide
Developed by the dermatologists of Skin Care Guide

Diagnosing Cold Sores

Diagnosing Cold Sores
When they do see doctors, in the vast majority of cases, a visual examination of the patient will confirm the diagnosis. The blisters around the nose and mouth area with tingling and irritation are hallmark symptoms of cold sores that are distinct (see cold sore images).
In some provinces, pharmacists could also diagnose.
When tests are conducted, a scraping may be taken from a blister using a swab. This can take several days, but will confirm the HSV on the fluid. Blood tests are another method of diagnosis that may be used when accuracy is important. These tests are not common procedure, however, and are generally reserved for special circumstances such as when a patient has a weakened immune system.

When should I see my physician?

Generally cold sores resolve without too much trouble over a period of 7 to 10 days without treatment, even for susceptible patients who tend to have recurrent cold sore outbreaks. Some good reasons to see a doctor include:
  • If you have a weakened immune system due to disease or medication that you are taking
  • If the cold sores persist for longer than 10 days
  • If you suspect that the condition may not be a cold sore
  • To obtain prescription drugs that help combat cold sore symptoms