Results of standard series patch testing in patients with occupational allergic contact dermatitis.

Background: In the workplace, the skin is at high risk of exposure to chemicals and other contaminants, and occupational dermatitis is an important field of study.

Methods: We evaluated 230 patients referred to our clinic because they were affected by dermatitis suspected to be of occupational and allergic origin. They were tested with the allergens of the GIRDCA standard series, and with supplementary series when indicated.

Results: Among the 230 subjects, 49 were positive only to supplementary series (26.3% of all allergic contact dermatitis), while 130 (69.9% of all allergic contact dermatitis) were considered to have an occupational allergic contact dermatitis diagnosed by the standard series alone. The most frequent occupations of the patients were health care workers and hairdressers/beauticians. The most common agents responsible for occupational allergic contact dermatitis were metals and para-phenylenediamine.

Conclusions: As the standard series detected a relatively low proportion of occupational allergic contact dermatitis, it is not adequate to recognize an occupational allergic contact dermatitis, certain supplementary series should also to be tested. However, even if such occupational series are used, we remain likely to continue to underestimate the frequency of occupational allergic contact dermatitis, because workers come into contact with a large number of substances that are often unknown.