(Concern) How do I treat sunlight allergy? Is there no treatment method?

I have a sunlight allergy. When my skin is exposed to sunlight for more than 10 minutes, I develop hives. Therefore, even in the height of summer, wearing a wide-brimmed hat and arm covers is essential. It was okay in winter, but as the weather warmed up and I exposed my neck and hands, I developed hives again. I saw on the internet that there seem to be others with sunlight allergies besides me. However, I have never come across any information about treatment or ways to improve it. Is there really no way to resolve a sunlight allergy? It makes daily life very difficult.