Is fluoride varnish contraindicated for patients who have a peanut or tree nut allergy? We are always having a debate about this at our office. I have read the ingredients on the fluoride varnishes, and none state any nut in them, only tree rosin.
The concern as you mentioned is if the patient has an allergy to rosin. Rosin, also known as colophony is the sap or sticky substance that comes from pine and spruce trees. Its "stickiness" lends itself to being used in a wide range of products that are used on a daily basis. Colophony can be found in the following items: cosmetics (lipsticks, mascaras, eyeliners, nail varnish), medicines (wart removers, hemorrhoid creams), toiletries (hair removing wax, sunscreens), adhesives (sticky plasters, tapes), household items (shoe wax, polish for shoes and cars), chewing gum, and dental products (dental cements, impression material, and fluoride varnish). A rosin allergy is confirmed by an allergy patch test. The intraoral reaction in an allergic individual would include acute allergic contact stomatitis or acute contact dermatitis if in contact with perioral skin. The inflammation is usually confined to the site of contact. Difficulty breathing can also be a hypersensitive reaction to rosin. So do patients with a peanut or tree allergy also have an allergy to rosin?
According to the Preventech website (makers of Vella 5% Sodium Fluoride Varnish) available at http://www.preventech.com/faq.htm the rosin used in Vella Varnish is extracted from pine stumps (not from living trees) so it does not contain tree sap. They also state, “This source combined with further synthesis during the manufacturing process greatly reduces any adverse reaction to rosin products due to tree nut allergies. However, as with any medical issue, patients should consult with his/her health care provider.”
A search of the literature shows two case studies reported in 1994 and in 2006 1,2 in which a colophony hypersensitive patient developed contact stomatitis after dental treatment with a colophony-containing dental product. These articles do not report a peanut or pine nut allergy. However we cannot rule out a cross-reaction between pine nuts and colophony so I recommend asking patients with peanut or pine nut allergies to consult with their physicians to determine if they are also hypersensitive to rosin/colophony before applying dental varnish. This would also be good for the patient to know this information since rosin is found in so many everyday products.
References 1. Bruze M. Systemically induced contact dermatitis from rosin. Scand J Dent Res. 1994 Dec;102(6):376-8.
2. Sharma PR. Allergic contact stomatis from colophony. Dent Update. 2006 Sep;33(7):440-2.