Sun damage to the lower lip is very common for people that spend a lot of time in the sun. The lower lip especially because even when wearing a hat, low lower lip is still exposed most of the time. What you are describing however sounds more like an angioma of the lip. If it is not an open sore and looks like it is just under the skin, then most likely it may be an angioma. An angioma is a benign lesion made up tiny vessels. If this is the case then I would not worry about it. However it is always a good ideal to consult with a dermatologist or and oral surgeon.

Good Luck!

Hello,
Thanks for writing in.
I read your problem,as you provided the detail,your dentist is right this is because of sun exposure.
The reason could be-
1.Actinic chelitis
2.Angioma.
So i will suggest you visit An oral surgeon as soon as possible and get the thorough examination done including biopsy.
And after final diagnosis take a proper treatment accordingly.
Nothing to get worried.
Take Care
Dr.Gunjan Gupta

Hello
Welcome to HCM
I would like to tell you that there are few possibilities & to rule out its important to know the sign & symptom like:-
-if it occurs at corner of mouth & causes itching then it can be angular cheilitis
-it can be angioma if it is painless & disappears on stretching, you can get blanching test done to rule out.
For more detailed diagnosis need to go for biopsy.

Take Care
Regards
Dr.Neha