Thank you for your inquiry.
To my knowledge, and based upon a literature search, there has been no documented association between nickel allergy and eosinophilic esophagitis. In addition, it follows that I could find no evidence in the literature that a nickel-free diet would be beneficial in patients with eosinophilic esophagitis. However, I doubt that such a diet would be of help because when one speaks of allergy to nickel, in most instances one is referring to a delayed hypersensitivity reaction which would not be associated with eosinophilia. There are of course cases of occupational asthma which demonstrate IgE against metals (1), but the route of sensitization is via the respiratory tract and not the gastrointestinal tract.
For these reasons, I would think that nickel would be highly unlikely as an allergen producing or exacerbating eosinophilic esophagitis in your patient, and would personally be reluctant to place him on a nickel-free diet.
Thank you again for your inquiry and we hope this response is helpful to you.
1. Murdoch RD, Pepys J, Hughes EG. IgE antibody responses to platinum group metals: a large scale refinery survey. Br J Ind Med. 1986 January; 43(1): 37-43.
Phil Lieberman, M.D.