Is p‐tert‐butylphenol‐formaldehyde resin (PTBP‐FR) in TRUE Test® (Mekos test) sensitizing the tested patients?

Abstract

Retesting did not add information regarding causes of possible sensitization. Analysis showed that the resin used in TRUE Test® has a lower degree of polymerization or condensation, which may enhance its sensitizing properties. A follow-up of late reactions to PTBP-FR in TRUE Test® should be carried out.

High prevalence of contact allergy in adolescence: results from the population‐based BAMSE birth cohort

“…Allergy to PTBP‐FR was also common in adolescents in this study. This allergy has not been shown to be so prevalent in previously published population‐based studies [0.9% in a study performed in 1995–1996 ; 1.4% in 2000–2001 ], with the exception of one, where the prevalence was exceedingly high (13.8%) . Because of the late development of some reactions in previous studies, patch test sensitization has been suggested as an explanation .…”

Active sensitization to cadmium, tin, and indium

“…Active sensitization is thought to be uncommon, amounting, according to some series, to 0.1% of all reactions . Some allergens have been associated more frequently with active sensitization, such as p ‐phenylenediamine , acrylates , p ‐ tert ‐butylphenol‐formaldehyde resin , chloracetamide , isothiazolinones , and Primula extracts . The literature concerning active sensitization is sparse and confusing, being almost exclusively based only on isolated cases or retrospective studies .…”

PTBP‐FR and TRUE Test®

“…Six months before testing, one of the latter subjects (subject 1) had purchased a watch strap to which she had developed an eczematous reaction. Although the authors stated in the brief case report that the strap was sent for chemical analysis, they did not identify the contents, and indicated that the results 'possibly indicated active sensitization to the PTBP-FR' (1). From the results of the gas chromatographic-mass spectrometric analysis, we later learned that PTBP-FR monomers were present in the glue of the watch strap, which the authors estimated contained 80 mg of PTBP-FR.…”

“…To the Editor, A recent article on p-tert-butylphenol-formaldehyde resin (PTBP-FR) in TRUE Test ® suggests that this patch may be sensitizing patients on whom it is tested (1). As the manufacturer of this product, I would like to point out a few additional considerations.…”

“…Because the dose per unit area when testing with TRUE Test ® is 6-10 times lower than when testing with 1% PTBP-FR in pet., Stenberg et al concluded that dose per unit area could not explain the suspected sensitization (1). They therefore compared the chemical analysis of the TRUE Test ® PTBP-FR with previously analysed constituents, which served as reference materials.…”