Greetings to all here. I am a 60 y/o white male, I [...]

Greetings to all here. I am a 60 y/o white male, I have a skin issue that was diagnosed as psoriasis about three months ago. I had red spots show up on my arms and legs. The spots were fairly smooth, not itchy and from 5mm to 10mm in size. I had four or five on each arm below the elbow and the same on each leg below the knee. Dark red at first but fading and disappearing, after about five weeks with the application of the prescribed steroid ointment.
A new wrinkle, Prior to these spots showing on my arms and legs I had a itchy welt appear on my lower left forearm near the elbow. I thought it may have been a mosquito bite and I did not mention it to the physician. Now about a month ago this itchy welt makes another appearance very near the site of the first. Being acutely aware, I immediately apply the steroid to the welt. The next day the welt is gone but three red spots show up on the upper forearm.
Yesterday the itchy welt makes its third showing, again I quickly apply the steroid to it. This morning I have a new red spot on the outside of my left ankle.
I do not think the itchy welt is a mosquito bite. I don't know if the itchy welt is related to the red spots, but it sure seems coincidental.
Have any of you all ever known of such a malady? About a three month wait to see a dermatologist around here. Would it be worthwhile to have the itchy welt tested while it is visible or have the red spots cultured?