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

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.

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.

A retrospective study was performed of patients patch tested to PFR2 between 1 January 2003 and 17 June 2020.

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%).

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.