Hi there. Any one of the medications you are using may be the culprit. It may be unrelated & related to some food/colouring agents. Morphine
has long been implicated as a major cause of similar lesions. It's good you stopped it. One can only ascertain on the ground (treating physician). To improve your Quality of life, topical mid potency steroids
may be the way forward couple with some non-sedative antihistamine. Hope this helps. Cheers & God luck!