Immunologic Unresponsiveness Appearing after Topical Application of Contact Sensitizers to the Guinea Pig

Abstract

Following the topical application of a sensitizer, a state of haptene-specific unresponsiveness to the compound regularly appears. This was demonstrated with three sensitizers: p-nitrosodimethylaniline (NDMA), dinitrochlorobenzene (DNCB) and chlorprothixene (CPT). Unresponsiveness may appear following application of minute quantities of a sensitizer (e.g., 25 γ NDMA) to the skin without further exposure to the compound prior to challenge. In the case of NDMA, unresponsiveness develops to maximum expression within 40 days of the initial topical exposure; unresponsiveness to a weaker sensitizer such as CPT appears more rapidly. A quantity of NDMA which is sufficient to induce unresponsiveness when put on the skin usually elicits a mild degree of sensitivity also. In the case of CPT, however, unresponsiveness is readily produced by topical applications which produce no detectable degree of sensitivity.