[In vitro testing for allergic contact dermatitis].

Patch testing is the standard method to identify allergic contact dermatitis. Simple, safe and accurate in vitro methods identifying contact allergies would offer both theoretical and practical advantages. Using the lymphocyte transformation test (LTT), allergen-specific lymphocytes central to the pathogenesis of Type IV allergies can be identified. Various studies have assessed the value of LTT in the diagnosis of contact allergies. The current assessment is that the test can be helpful in distinguishing between irritant and allergic reactions. LTT is especially useful in demonstrating drug allergies and can also be employed to prove sensitization to gases or toxic substances. At the present time, it is not an alternative for patch testing in daily practice.