I am very allergic to any man-made fabrics. My allergies consist of breathing in the odors of the chemicals in the fabrics. The chemicals stop my breathing muscles from working and I must use oxygen to get me through the very bad reactions. Ironing them makes it much worse. I do break out in hives and rashes when I use or wear clothes made of such fabrics. I use only natural fabrics and I must wash them in baking soda and vinegar a few times before using the fabric or wearing the clothes. I have to stay away from synthetic fabrics in the stores, too. I hope you can figure out what is causing your problems. :)