Is there a way to manage sun allergies during the summer?

I am writing to inquire about the allergies that have been causing me a lot of trouble and stress lately.

It is none other than a sun allergy... I didn't originally have it, though I wonder if it's been about 10 years? Suddenly, after being exposed to sunlight, it started itching, then turning red and stinging. It happens on the backs of my hands and the insides of my arms, too. It seems like I get an allergic reaction whenever I'm exposed to sunlight, but the back of my neck is especially painful.

The back of my neck is really stinging. If I don't take proper care of it and get exposed to sunlight, an allergic reaction flares up; after a few days, it starts with itching and then turns into stinging. It feels like needles are pricking the back of my neck, especially when I have a cold sweat or am nervous. That is when it stings the most. I should be applying sunscreen properly starting in the spring, but since I sweat a lot, I don't really apply it, so it's a vicious cycle. I do apply aloe vera to cool it down at home after sun exposure, but...

I'm wondering if protecting my skin with something like sunscreen is the best way, or if there are ways I can get help from a dermatologist.