Hello Doctor, I Have Red Itching Rask All Over My

Hello Doctor, I have red itching rask all over my stomach since last 5-6 days .It was initially in a limited area of the stomach now its all over. I also suffer from Pemphigus Vulgaris since last year & half .Recently had Rituximab treatment which I went through last year too & it helped a lot. My family physician has given me Reactin.Should I apply some cream too?