When I am out in the sun I get an itchy rash on my forearms the next day I get a slightly raised hive like rash on my face. I always use sunblock but the current rash was after sunblock and minimal sun exposure. My ANA was negative (1/40), as were other lupus indicators. at my last test but my Anti-Ro SSA was positive. I have been diagnosed with discoid/cutaneous lupus on the scalp x7 years. I also have autoimmune thyroid disease. After sun exposure I'm totally wiped out, like I could sleep for a week, not that w/o it I am energetic. I have been blaming thyroid levels on the constant fatigue that I have been experiencing for the past 9 months.
I'm not sure if it's an allergy to the sunblock or a Lupus flare that is just not caught by blood tests taken at the right time. It's very frustrating.
Re: Facial Rash... sun induced or sunblock allergy?
It is most likely from the lupus, since sun exposure also makes you feel wiped out for a week after. The patch test is a good idea. Some sunscreens with PABA are allergenic for some people, but if you got the rash on areas where you didn't apply sunscreen, then it is a photosensitivity reaction. An ANA of 1:40 is positive, but considered borderline pos by many. It can still be meaningful given the symptoms that go with it.