only study I know of offhand is the one below with self reported American peanut allergy rates of 0.8%. It's a few years old and I thought our rate was reckoned to be 1% then.
Prevalence of peanut and tree nut allergy in the United States determined by means of a random digit dial telephone survey: a 5-year follow-up study.Sicherer SH, Muñoz-Furlong A, Sampson HA.
Department of Pediatrics, Mount Sinai School of Medicine, New York, NY 10029-6574, USA.
Current government advice is avoid nuts if you're atopic - but its not evidence based and various people are trying to get it changed.