Comparative study of formaldehyde 2% in aqueous solution vs TRUE Test in detecting formaldehyde sensitization

Abstract

The optimal formaldehyde (FA) concentration for patch testing that allows to identify true FA sensitization has been studied and discussed over time. Several studies support that FA 2% aqueous solution (aq.) is the most effective concentration for identifying true FA sensitization without causing too many irritant reactions.1 Thus, in 2016, the Spanish baseline series was updated by the “Grupo Español de Investigación en Dermatitis de Contacto y Alergia Cutánea” (GEIDAC) and the test concentration of FA was modified from 1% to 2% aq.2

However, several parameters may affect the results, including technical methods such as diagnostic patch testing with support materials.3, 4

We present a prospective multicentre Spanish study that compares agreement and diagnostic accuracy of positive patch test reactions to FA 2% aq. with FA in TRUE Test.