The utility of the TRUE test in a private practice setting

Studies suggest that the Thin-Layer Rapid-Use Epicutaneous Test (TRUE Test) may be inadequate to completely diagnose a significant number of patients with allergic contact dermatitis (ACD).

To study the usefulness of the TRUE Test as a triage tool in a private practice setting.

A retrospective chart review of patients who were patch-tested with the TRUE Test between July 1, 2000, and June 30, 2004, in four private dermatology practices was conducted.

Of the 183 patients evaluated, 50.8% had at least one positive reaction, 31.7% had a diagnosis of ACD, and 24.0% were suspected to have ACD from other allergens. Of the patients with positive reactions, 62.4% were determined to have reactions that were of present relevance.

The TRUE Test allows patients with dermatitis to be triaged systematically in a private practice setting. It is important to supplement patch testing with the patients' personal products, especially in cases of facial or periorbital dermatitis, and to be aware of potential false negatives, particularly with fragrance and rubber additives.