Making the Diagnosis
Cold sores have clear and obvious symptoms, so there's no need for a battery
of tests. In any case, they're rarely a matter for the doctor. However,
you should see a doctor about any redness and pain in the eye, any fever over
100°F (38°C), or if there is thick yellow-white fluid coming from the
blisters. This may be a sign of bacteria in the wound. Your doctor can check
the fluid from the blisters for the presence of bacteria. A doctor should also
be seen if lesions are present for more than 14 days, if the lesions occur more
than six times a year, if or you have a cold sore in addition to a condition
that weakens your immune system.