After spending my teens and 20's trying to get the darkest tan possible, and a few impromptu outdoor excursions without sun protection (usually a roam through an old cemetery), I have permanent sun damage on my lower arms, hands, and neck. Our grandmothers may not have known that sun causes skin cancer, but they knew that LADIES didn't have tans. Thus, the white gloves, hats, and parasols!
I have become diligent about using sunscreen, and my current favorite is a CVS brand, a dry lotion (not greasy and sticky!) which I can use on my face under makeup. It is 100 SPF with UVA AND UVB protection. Unfortunately, I'm not good at remembering to reapply during the day. Even that may not be enough protection. I believe that I am experiencing my first bout with something called Polymorphous Light Eruption, which is simply an allergic reaction to the sun.
The reaction began as a bright pink raised dime size area on my arm. I assumed that it was an insect bite. The next day, I found the same type of thing on my left arm, and for days afterward, it spread as a rash on both arms. Two days ago (two weeks after the initial outbreak) it erupted it welts on my neck and chest.
Evidently, my dermatologist has never heard of it, because he immediately diagnosed it as contact dermatitis combined with an allergic reaction to Benadryl cream. Actually, The rash had spread for two weeks, and I had used the Benadryl for a couple of days two weeks ago. Even though the puzzle pieces were not fitting, my doctor stood firm on the most common diagnosis for an idiopathic rash. I was determined to understand what had happened so that I could avoid it in the future, so did my own research.
I take a daily walk in a local park, and often sit on the bank of the pond and photograph the ducks and geese. Even with sunscreen, and even late in the afternoon, my neck and lower arms were getting a lot of sun exposure. The recommended treatment is hydrocortisone cream, so I'll be using it every day while I'm mindful of reapplying sunscreen and avoiding the sun as much as possible in mid-afternoon.
I just wanted to put this out there for anyone who may experience a rash in areas exposed to the sun. What kept me looking for answers was the "contact dermatitis" diagnosis in the very areas that were not in contact with anything! Polymorphous Light Eruption can affect people of all races and skin coloring.