Can the sun cause fever blisters?

Yes, UV rays from the sun can trigger fever blisters (cold sores) if you already carry the virus. Since I manage diabetes, my skin is quite sensitive, so I always apply a good sunscreen and lip balm before going out.

Absolutely, sun exposure is one of the biggest triggers for cold sores. I get them every time I go to the beach. My tip: always use a lip balm with SPF 15 or higher, and avoid direct midday sun. It works wonders.

Yes, sun exposure can trigger them. But please be careful—I once mistook a severe skin infection for simple sun blisters, which delayed my treatment. It is always best to let a dermatologist look at it.

At this age, just standing in the sun for five minutes triggers either a headache or these annoying blisters on my lips! Yes, the sun is a major trigger, so wear a hat and look like a tourist—it helps!