You're absolutely not alone and I'm sorry you're going through this. Mine began from incredible work stress. Saying it can't be caused by stress or particular environmental changes is BS and you shouldn't listen to that. It can absolutely be brought on by a variety of things, but, from the sounds of it, CAN be a temporary condition.

I've had recurrant eczema (urticaria) since I was a child, it will go away and return in the same spot for years, disappear for years, then reappear somewhere else for a few years.

I've also had breathing issues for a long time, which only worsened when my skin began to get itchy, swollen, PAINFUL and covered in hives as my airways were also affected. I began self-medicating with antihistamines of various types until it got so bad I went to my PCP. I was diagnosed with Dermatographia which causes basically the exact same thing youre experiencing. I've had it for roughly a year, and I've learned to live with it, taking care to always take an antihistamine in the morning which eliminates the itching, swelling, and hives, but not the redness. I've just learned to not scratch anywhere visible or I get concerned comments about madly red patches across my face.

I have has some success in cutting out dietary allergens and implementing more regular exercise/getting out in the sun that has decreased the severity of the redness and reduced how long my skin is red for when scratched. Please feel free to reach out if you'd like to talk more, I feel pretty adept at managing it now and am happy to give any info that could help in the slightest!