Allergic contact dermatitis to phenol-formaldehyde resin at a single tertiary dermatology centre.

ABSTRACT

BACKGROUND: Phenol-formaldehyde resin 2 (PFR2) has been shown to be a useful marker of contact allergy (CA) to various phenol-formaldehyde resins. These compounds are used in several industries as solids, powders, or semisolid resins, and are known to be sensitizing agents. OBJECTIVES: The aims were to investigate contact allergy to PFR2 in a single tertiary dermatology centre, to examine associated simultaneous allergic reactions, and to identify cases of allergic contact dermatitis (ACD) to PFR2. METHODS: A retrospective study was performed of patients patch tested to PFR2 between 1 January 2003 and 17 June 2020. RESULTS: In all, 337 of 7922 patients were tested to PFR2 and 16 (4.7%) reacted. Of those 16 individuals, six (37.5%) had a relevant reaction (1.8% of total). Simultaneous allergic reactions were noted to colophonium in eight (50.0%) patients, Myroxylon pereirae in five (31.3%), and fragrance mix I (FMI) of three cases (18.8%). CONCLUSION: Contact allergy to PFR2, even in a selected population of patients, is uncommon. However, patients exposed to plastics and glues, or who work with wood products should be routinely patch tested to a plastics and glues series containing PFR2. We recommend that all centres include PFR2 in their plastics and glues series.