Failure of periodic ultraviolet radiation treatments to prevent sensitization to nitrogen mustard: a case report.

We have reported that prior ultraviolet radiation (UVR) exposure significantly delayed development of contact sensitivity to nitrogen mustard (Halprin et al., 1981). We felt that this effect was due to disruption of functional Langerhans cells in skin by UVR and suggested that periodic UVR treatments might prevent sensitization to the mustard. We now report on a patient with mycosis fungoides whose epidermal Langerhans cell count was monitored with the ATP-ase stain in order to determine when such 'booster" UVR therapy was to be given. Our attempts to interfere with Langerhans cell function in this manner failed to prevent delayed contact sensitivity to nitrogen mustard and may have been partly responsible for the development of contact urticaria to nitrogen mustard after 28 days of use. Whether the reaction was a delayed, cell-mediated reaction, or an antibody mediated reaction is not clear, but the use of UVR did fail to prevent contact sensitivity to the nitrogen mustard in our patient.