I Sleep On A Leather Recliner Due To A Shoulder

I sleep on a leather recliner due to a shoulder replacement that makes lying flat terribly painful. About 3 weeks ago I started experiencing what appeared to be insect bites with an allergic reaction that appeared to have occurred during the night. The areas of the "bites" were very swollen over a larger area and itched mercilessly. I have several allergies including dust mites. I now know that dry skin is what dust mites crave and they really are not biting me. However, I do not have dry skin. After 3 weeks of this horror, our building's exterminator came and examined my recliner. He concluded that the problem is dust mites in the dust under the recliner and probably on the leather and upholstery. He told me to vacuum aggressively under the recliner and behind the leather flap at the back of the chair as well as every crevice that I could get the nozzle into. I did this. I slept on the recliner that night and in the am I had no new skin lesions or swelling. I thought that I had mastered the problem. The next night with all newly clean bedding on the recliner, I wasn't so lucky. In the am I had new large welts on my arm, my back, and my backside. My arm was red and swollen from my wrist to my shoulder. I am cleaning the my skin with alcohol and when dry, applying Calagel which has been helpful in reducing the intensity of the itching and spread of the swelling. I went to the hardware store looking for a solution but found nothing to use that doesn't contain any of the substances to which I am allergic. I left and decided to try Lysol which I did last night. During the night I was awakened by extreme itching and very large areas of swelling. I used the alcohol and Calagel and was able to return to sleep. None of our other furniture appears to be affected. My husband sleeps on the bed and he has experienced none of this. The sofa also does not appear to be a problem. We have one 5' x 7' area rug that is of synthetic material. It's been vacuumed daily. I have 2 questions: 1. How do I get rid of the dust mites and is there a less allergenic substance that I can use. And how do I use it? Is there a procedure that will be more effective? And 2, how do I treat my allergic reactions and itching. By the way, I take Zyrtec daily. Any help and words of wisdom will be much appreciated. I am 70 years old and quite healthy despite the shoulder injury and a bunch of allergies. Thank you very much, Iris