Does mirtazapine cause itching all over the body?

Maybe (not): Any drug can cause just about any side effect. Common ones are itching, rash & nausea/vomiting. While info re Mirtazapine includes various skin reactions, there's no specific mention of total body itch in either of two readily available references. Check out https://online.Epocrates.Com/noframe/showpage.Do?Method=drugs&monographid=1171 (requires free reg) & http://www.Drugs.Com/mirtazapine.Html.

Occasionally: Interestingly, Mirtazapine is sometimes given to treat itching, but itching is also a possible (though uncommon) side effect. Occasionally this could be a sign of a serious allergic reaction. The only way to see if the itching is caused by it would be to stop it and restart it if the itching goes away, but i advise you discuss this with the doctor who prescribed it as soon as possible.