Comparison of patch test results among white Europeans and patients from the Indian subcontinent living within the...

There are few studies comparing the incidence of allergic contact dermatitis among different racial groups living within the same community.

The objectives of this study were to compare white European patients with Fitzpatrick's skin phototypes (FSP) I to IV and patients from Indian, Pakistan and Bangladesh with FSP V living within the same community. Referral rates for patch testing, incidence of contact allergies and differences in contact allergens found were assessed.

All patients referred to the Contact Dermatitis Unit at Dewsbury and District Hospital between 2004 and 2006, inclusive, were included in the study. All patients were patch tested to the British Contact Dermatitis Society standard series, plus other series according to their clinical history, occupational history and clinical findings.

Four hundred and thirty-five consecutive patients from the patch testing clinic were included in the study. Fewer patients from the Indian subcontinent underwent patch testing (11.5%) than would have been expected for the size of the local population (18%). Fewer patients from the Indian subcontinent (44%) had one or more positive reactions compared with the white European patients (56%). No significant differences in the contact allergens responsible were detected between the two racial groups.

There is a lower incidence of positive patch test results among patients with racial origins from the Indian subcontinent compared with white Europeans. This modest difference could be explained by a lower average age within the study population, and increased or differing exposure to contact allergens rather than demonstration of variability in the susceptibility to develop contact sensitivities following equal exposure.