Sun spots/Itchy/Blotchy skin from the sun

Whenever I stay in the sun for a little too long I get large areas on my chest and shoulders that are blotchy from the rest of my skin and most irritating, they are very itchy! Does ANYONE know what this could be and how I could possibly prevent it? Is there something I can do prior to going in the sun to prevent it? Or is there something I can put on it after I get it to reduce the itchiness, irritation and blotchiness? Please help!! Thank you!!

[Vanessa Lacuesta]

Hi

This sounds like a photosensitivity reaction. Photosensitivity reactions may range from solar urticaria to more severe reactions to UV rays. In your case, this may be solar urticaria. “Solar urticaria is an uncommon disorder sometimes difficult to treat. It is characterized by the occurrence of typical whealing reactions on exposed skin a few minutes after sun exposure. The reactions resolve 1 to 5 hours after sun exposure ceases.”
Source: http://www.ncbi.nlm.nih.gov/pubmed/10804306

This type of photosensitivity may present with rash, hives and itchiness on sun exposed skin. Taking oral antihistamines prior to sun exposure may help. However in severe forms, you may need  desensitization therapy. Applying sunscreen may help unless this also aggravates the flares.

Does the rash resolve in a few hours?

[Escojos]

Within a week, the blotchiness areas will come about the 2nd or 3rd day of being in the sun and will remain a few days after the week is over. I usually put regular lotion on the areas to moisturize them so they wont itch so much, this helps some. I've also learned of something called Tinea Versicolor and have seen pictures and my case looks very similar to that. However, I am not certain because that disorder doesn't say much about being in the sun, just that is caused be hot and humid weather - which I guess being at the beach would be hot and humid?
This year I think I will put a high SPF on my chest and stay out of the sun. What a bummer, I will be in Aruba!!!