Im 54years Old I Am Experienceing Extreme Rash Moving From

Im 54years old I am experienceing extreme rash moving from place to place sometimes it feels like a mosquito bite. I went to a skin specialist and he told me it could be allergic reaction, i don't think so because he didn't take my blood test. This thing has been bothering me for a year,also I've been experienceing discharge,joint pain and muscle pain. Any info please I appreciate it

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