Diagnostic value of the lymphocyte proliferation test in nickel contact allergy and provocation in occupational coin dermatitis

The lymphocyte proliferation test (LPT) was compared with the patch test in the diagnosis of nickel contact sensitivity Of the 21 subjects with nickel contact allergy, the patch test detected 28 (95%) The subject remaining negative in the patch test was positive in the intradennat test. 18/21 subjects with nickel contact sensitivity were positive in the LPT. Where as in the control group 2/23 was false positive These results were obtained at nickel sulfate concentrations of less than. 10 μg/ml higher concentrations led to nonspecific lymphocyte stimulation. 3 nickel-sensitive cashiers with suspected coin contact-induced deterioration of their hand eczema were challenged by having them count nickel-containing coins daily for 15 min. 2 of them developed vesicular eczema on their palms and fingers in 2 to 3 days. The present results show that the LPT is a reliable additional test in the diagnosis of nickel contact sensitivity. Furthermore, provocation is a valuable procedure when assessing the relevance of nickel contact in occupational hand eczema in certain occupations.