I just got PMLE for the first time. All it took was a walk to the car. My chiropracter said it was due to a calcium deficiency. But, I also take advil regularly (trying not to) and I wash hair with a dandruff shampoo that has coal tar in it. Plus I have pinched nerves. I suspect all are contributing culprits. He recommended I take Cateplex F with calcium. This will take awhile to work. So, in the mean time I am trying not to scratch (not much luck there) and a topical cream. I started with aloe with lidacane but that didn't do much. I am currently using a cortizone 10 cream which gives 1 to 2 hours of relief. I am also avoiding the sun as much as possible. Hope that helps.
I had PMLE first starting in 2009, other symptoms where lupus type rash on face. But, this was not lupus. But, eczema. PMLE rash would come from sun exposure. I went totally gluten free for lent one year. I have been rash free every since.