Chrome allergy rarely occurs by touching the chrome finishings we often associate with the metal. Chrome allergy is linked to a reaction to chromium salts, which are used to manufacture other products such as cement, mortar, leather and paint. Most sufferers of this allergy are from occupational exposure.
Chrome allergy has also been noted after transplantation surgery, mostly associated with hip and knee replacements.
I have put together some more comprehensive resources at http://www.allergyresources.co.uk/Chrome.php
The allergy resources page for chrome covers the key allergens, which allergic syndromes are linked to this allergy and other foods which are commonly cross reactive with chrome.
There is also regularly updated links to useful websites specifically for chrome allergies and the latest research papers on the topic.
If you have multiple allergies and are interested in how they are linked or want to find out more about food allergies outside the usual top 14 then you can follow me on Facebook or Twitter, where I share a food allergy card every day of the week.