surface of the skin 20 by means of an in line contact adhesive 18 this adhesive layer 18 contains a set amount of corticosteroid a strippable release liner not shown adapted to be removed prior to application would normally be included in the packaged product in an alternate embodiment the system is attached by means of an adhesive overlay as is shown in fig2 the system 22 is comprised of a sensitizing drug corticosteroid reservoir 24 which is in the form of a matrix or carrier having the drug and the corticosteroid dispersed throughout the reservoir 24 is covered by an impermeable backing 26 which is preferably sized larger in circumference than the reservoir 24 means 28 for maintaining the system on the skin may be fabricated together with or provided separately from the remaining elements of the system means 28 as illustrated in fig2 takes the form of an adhesive overlay in some instances an adhesive overlay 28 is preferable over an in line contact adhesive 18 as shown in fig1 this is true when there are elements present in the matrix which may adversely affect the adhesive properties of most pharmaceutically acceptable contact adhesives for this reason impermeable backing layer 26 is preferably sized slightly larger than the reservoir 24 to provide a peripheral area around the reservoir 24 which would be free of any material which may seep from under the base of reservoir 24 and adversely interact with the adhesive in overlay 28 a strippable release liner 30 would also be provided with the system.