How to alleviate psoriasi. Have allergy.

Have been having psoriasis since I am 3/4 yrs along with a severe allergy. I had open-heart surgery in 2003. I don't know what kind of psoriasis I have and would like to know it. My symptoms usually started with a cold followed by high temperature (sometimes very high), then my whole body turn a red purplish color and my body would be covered in pus. The duration of my illness vary, usually covering 3/4 month for full recovery (when I was younger) and 1-3 months nowadays (1 month recovery is very rare). We (my family) had consulted different doctors but I did not respond to any treatment given to me but instead react very severely to them. Due to this I stop consulting doctor for a very long time (more than 10yrs) now but due to today's rapid medical advancement, I am somewhat hopeful that I can find help for my condition. I never knew exactly what trigger it as I also have allergy.