Camomile is a less common food allergy – none of the allergens it contains have been recognised by the World Health Organisation.
Contact reactions linked to camomile have been linked to nobilin (Sweet chamomile) and desacetylmatricarin (German chamomile). Both are sesquiterpene lactones and are commonly used in cosmetics.
I have put together some more comprehensive resources at http://www.allergyresources.co.uk/Camomile.php
The allergy resources page for camomile covers the key allergens, which allergic syndromes are linked to this allergy and other foods which are commonly cross reactive with camomile.
There is also regularly updated links to useful websites specifically for camomile 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.