redness on arm

Is any one has solution to cure itchiness on my arm? I do not know its cause.

I had reduced my fat intake so low, for so long, my skin was very dry. My nutritionist had me add either 10 nuts or one tablespoon of avocado daily to my diet daily to put good fats back in. I do the avocado once or twice a week, almonds or pistachios the other days of the week. That, combined with a good hydrating body creme helped me.

But if you are having an allergic reaction or psoriasis or something else, what worked for me will likely be ineffective for you.