Recently published guidelines only recommended in vitro assays for atopy screening by the determination of specific IgE antibodies in occupational cutaneous allergic diseases. However further indications include latex allergy, occupational drug allergy and wasp/bee venom allergy. The lymphocyte transformation test may be an alternative to the patch test, in order to differentiate allergy from irritancy, or it may be an alternative to the patch test if hazardous compounds such as carcinogens are the possible antigens.