Aqueous solutions of mechlorethamine (Mustargen) hydrochloride (0.055 to 0.00625%) have been used in courses of seven to ten days on lesions of psoriasis in 42 patients. A significant involutionary effect was obtained with the 0.0125% to 0.05% concentrations, particularly on the trunk. The rate of contact sensitization ranged from 50% to more than 80%, and was highest with the 0.05% concentration. Occasional Koebner reactions and paradoxical results were noted. The high rate of sensitization precludes the use of this agent in the practical management of psoriasis.
Zackheim HS, Arnold JE, Farber EM, Cox AJ. Topical Therapy of Psoriasis With Mechlorethamine. Arch Dermatol. 1972;105(5):702-706. doi:10.1001/archderm.1972.01620080032009