Transdermal patches can be a very precise time released method of delivering a drug. Cutting a patch in half might affect the dose delivered. The release of the active component from a transdermal delivery system (patch) may be controlled by diffusion through the adhesive which covers the whole patch, by diffusion through a membrane which may only have adhesive on the patch rim or drug release may be controlled by release from a polymer matrix. Cutting a patch might cause rapid dehydration of the base of the medicine and affect the rate of diffusion.
Weaker topical steroids are utilized for thin- skinned and sensitive areas, especially areas under occlusion, such as the armpit, groin, buttock crease, breast folds. Weaker steroids are used on the face, eyelids, diaper area, perianal skin, and intertrigo of the groin or body folds. Moderate steroids are used for atopic dermatitis , nummular eczema , xerotic eczema , lichen sclerosis et atrophicus of the vulva , scabies (after scabiecide) and severe dermatitis . Strong steroids are used for psoriasis , lichen planus , discoid lupus , chapped feet, lichen simplex chronicus , severe poison ivy exposure, alopecia areata , nummular eczema, and severe atopic dermatitis in adults. 
It is important to use the correct amount of topical steroid for your eczema, as instructed by your healthcare professional. Topical steroids should be applied with clean hands so that the skin just glistens. It can sometimes be difficult to judge how much steroid to use and there are guidelines on the amount required to cover body areas that are affected by eczema. These are based on the Finger Tip Unit (FTU), and explained in detail in our fact sheet which you can download as a pdf from the related documents to the right of this page.