Is Fluoride Varnish a Risk for Patients With Nut Allergies?

There is cause for concern if a patient has an allergy to rosin. Also known as colophony, rosin is a solid form of resin—a viscous hydrocarbon secretion of many plants, particularly coniferous trees such as pine and spruce. Obtained from liquid resin by vaporizing its volatile compounds, rosin is found in a wide range of frequently used products because of its sticky nature. Rosin is contained in the following items:

• Dental products (fluoride varnish, dental cements, impression materials)
• Cosmetics (lipsticks, mascaras, eyeliners, nail varnish)
• Medicines (wart removers, hemorrhoid creams)
• Toiletries (hair removal wax, sunscreens)
• Adhesives (sticky plasters, tapes)
• Household items (shoe wax, polish for shoes and cars)
• Chewing gum

A rosin sensitivity can be confirmed with an allergy patch test. The intraoral reaction in an allergic individual includes 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. It is unclear whether patients with peanut or tree allergies will also have a reaction to rosin. According to a manufacturer website, the rosin used in its fluoride varnish is extracted from pine stumps (not from living trees) so it does not contain tree sap. The site also states: "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 their health care providers."¹ A search of the literature shows two case studies reported in 1994² and in 2006³ in which a patient who was hypersensitive to colophony developed contact stomatitis after dental treatment with a colo phony-containing dental product. Neither article reports whether the affected individual had a peanut or pine nut allergy. A cross-reaction between pine nuts and colophony, however, cannot be ruled out, 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 fluoride varnish. This knowledge is also important for patients, as rosin is found in many products.

References

1. Preventech. Vella 5% Fluoride Varnish. Available at: preventech.com/ product/vella/#nofollow. Accessed July 29, 2015.
2. Bruze M. Systemically induced contact dermatitis from rosin. Scand J Dent Res. 1994;102:376–378.
3. Sharma PR. Allergic contact stomatitis from colophony. Dent Update. 2006;33:440–442.