I have a severe sun allergy, so I should be able to help out a bit on this one. :)
I have an autoimmune disorder called Systemic Lupus Erythematosus, thought to be genetic in my case (my grandmother and my great-grandmother were also sun-sensitive/had an allergy, though not the extent that I have) that mainly effects my organs. Basically what is going on is that my white blood cells recognize each other as foreign, and as such are continuously attacking each other. So in essence, my body is constantly trying to kill itself without my consent. How this effects me is I have a terrible immune system, I get sick easily, I am incredibly sensitive to bright lights, and my body has no defense against sunlight.
It ‘triggered’ when I was nine years old, and I started noticing that I would get sick, get rashes and burns easily when I was out in the sun (even with sunscreen) for more than about a half hour, and has slowly progressed to how it is now. Less than a minute outside during the day would kill me, and even split-second exposure leaves me with blood coming out of my pores, and sections of my skin boiling and even pieces of the flesh taken away in longer exposures. Luckily I am so pale that the scar tissue blends in with my skin tone. I also can’t see very well in bright lighting, and my eyes have adjusted so that I have wonderful night vision, but it hurts like anything to even try to look at something outside through my (UVA/UVB filtered) windows. I have been to dozens (literally) of dermatologists, and there really is no cure for my condition, and I haven’t responded to any treatments common for Lupus patients. My main dermatologist (who is one of the top dermatologists in the country) said that in all of his years of practicing, he has only seen one other patient with my exact disorder, symptoms and level of severity.
So to finally answer your question; from the sounds of it, you very well may have some form of photosensitivity, which is very common in natural blondes and redheads (myself falling into the latter category). Certain medications can cause increased sun-sensitivity, as well as certain disorders. Here are a few websites that discuss sun allergies at length.
And from personal experience, here are a few tips that should help with mild to moderate sun allergies. First off, invest in sunglasses, a sun-proof parasol, some full spectrum SPF30 (at least) sun-block, and wear long sleeves and gloves when out during the day. Here is a website where you can get some sun-proof clothing (including a parasol). Some of them may look a bit dorky, but they really are necessary for someone who is sun sensitive.
I hope this helps, and if you ever need to talk about it or any aspects of it (from tips on prevention to being made fun of because of it, etc) with someone who is/has been there, please just message me, alright? :)
Here are a few pictures of me, in case you are curious about how pale someone must be if they haven't been out in direct sunlight for a decade. ;)
· 1 decade ago