Three weeks ago I saw the dermatologist for my sort of annual visit. (Sometimes I let more time go by.) Everything looked pretty good, except I showed her a small rough spot on my upper chest. She was going to zap it with liquid nitrogen, but decided instead I should use flourouracil (chemotherapy) cream instead. I've had to treat a number of pre-cancers (actinic keratoses) before, and a couple of years ago I had a small basal carcinoma on my nose.
After a few days the spot turned red, showing that it indeed needed to be treated. The cream also seeks out nearby problems and causes them to light up, and apparently works through the bloodstream to find other spots. Within a few days I had an area on my chest (the V neck) diamond shaped about 3 1/2 by 3 inches, and two spots on my upper forehead.
You have to use the cream as long as you can stand it--2-4 weeks. In my case, 2 1/2 have weeks is normal. The result: red, raw, burning, itching skin. I am done with it now, except that I have new red spots to be treated at the base of my neck on one side.
What is annoying about this is I don't want to expose it to view, but having even a thin tee shirt covering it up is driving me nuts. At night it itches and drives me nuts.
So: The moral of the story I wish to make is this: Don't forget to put sunscreen on your upper chest, your cleavage, and whatever skin is exposed. Many many times I diligently covered my face and hands, but was wearing a shirt or V neck and forgot the chest.
When I was a kid, I was "prescribed" lots of sunshine. I was diagnosed with rheumatic fever at a time when antibiotics weren't widely used or even available. I needed that vitamin D so much that in the winter my folks put a sunlamp on me, mostly focused on my upper body. As a teenage my friends and I would take turns baking in each other's back yards (I never did get a decent tan) and on the 4th of July my family always went to the beach and got sunburned.
We know so much better now.