Colophony in Dentistry: Routes of Exposure and Reported Reactions.

Colophony is a solid form of resin derived from coniferous trees that has both adhesive and water-resistant properties. For these reasons, this allergen is incorporated into many personal care products, medications, and occupational materials, and is thus commonly implicated in allergic contact dermatitis. Dedicated "dental" allergen series often include colophony, but dermatologists are likely not well-versed on its use in a dental setting. There are several routes of exposure to colophony via dental materials, including periodontal dressings, cements, and varnishes. Contact with these products by an individual with a colophony allergy has the potential to produce oral reactions, but cases in the literature are sparse, with almost no publications on this topic in the past decade. This article reviews the existing cases of oral reactions to colophony and discusses their relevance in medical practice. The most common oral reaction identified was allergic contact stomatitis arising after dental interventions in which colophony-containing dressings or fluoride varnishes were used. Cases of allergic contact cheilitis, oral lichen planus, and systemic contact dermatitis have also been described. Both dentists and dermatologists should be aware of colophony's ability to produce allergic contact reactions, especially in the form of stomatitis or cheilitis. For known colophony-allergic patients, dermatologists should provide counseling regarding potential exposure in dental materials and procedures.