Intravenous desensitization to mechlorethamine in patients with psoriasis.

Eight patients with psoriasis who had developed contact allergy to mechlorethamine hydrochloride (nitrogen mustard) were subjected to a regimen of intravenous infusion of small amounts of the drug in an attempt to produce desensitization. Although three of eight developed negative patch tests and were presumed to be desensitized, only one patient was able to use the drug therapeutically, and then only for a period of eight months, after which allergy recurred. The other two patients whose allergic contact dermatitis was abolished by the infusions were unable to use mechlorethamine therapeutically because of pruritus. Seven patients experienced some adverse reaction to the infusion. Intravenous desensitization of psoriatic patients who are allergic to mechlorethamine was not successful enough as a useful clinical procedure to allow them to once again use the drug therapeutically.