Use of the North American Contact Dermatitis Group Standard 65-allergen series alone in the evaluation of allergic contact dermatitis: a series of 794 patients.

BACKGROUND: The "gold standard" for diagnosing allergic contact dermatitis is patch testing. Previous studies have not adequately addressed the validity and usefulness of the North American Contact Dermatitis Group (NACDG) Standard 65-allergen series alone as a screening tool in the evaluation of contact dermatitis.

OBJECTIVE: The purpose of this study is to examine the usefulness of the NACDG series of 65 allergens as an exclusive screening method in the diagnosis of contact allergy.

METHODS: A retrospective chart review of 794 patients referred for patch testing with the NACDG Screening Series with or without additional allergens was performed to determine the number of positive patch-test results. The study groups were analyzed to identify whether the positive reactions were to allergens in the NACDG Standard Series or to allergens in the supplementary group.

RESULTS: Of the 794 patients patch-tested between July 1, 2004, and July 1, 2006, 590 (74.31%) had a positive reaction to either an NACDG patch-tested allergen or a supplemental allergen; 386 (65.42%) patients testing positive for an allergen were positive to an NACDG allergen only, and 534 (90.51%) of the total positive reactors were positive for at least one NACDG test allergen.

CONCLUSION: As a screening tool, the NACDG Standard Series is substantially more efficacious than are more limited standard series when used exclusively in the evaluation of patients with allergic contact dermatitis. More extensive testing, including testing with suspected supplementary allergens determined by thorough history and physical examination, can improve upon the NACDG series as a means to investigate the full causes of contact dermatitis in any individual patient.