Outline features for chemical induction of delayed hypersensitivity.

The present paper attempts to set bounds for a qualitative and quantitative evaluation of immune-responses towards cellular mechanisms, as a tool for toxicological studies. It makes a plain distinction between the assessment of skin irritation and skin sensitization evoked by chemical haptens. Three well-known predictive methods to test delayed cutaneous hypersensitivity were used to elicit the reactions, either by epidermal patches or intradermal injections. The skin responses were scored according to the measurements of the oedema and erythema area. Hence, the specificity of the skin reaction was performed to verify the presence of possible cross-reaction amongst the chemical components used. These straightforward experimental features allow a more precise characterization of the cell-mediated reaction, nowadays, widely scattered amongst a few standardized technics or government reports. It may by concluded that the present work would help to separate an immunological response from other occurring phenomena.