Steoid & occlusive. As discussed in a prior answer, an occlusive dressing over a corticosteroid multiplies the concentration of that steroid up to a factor of ten. Cordran tape contains a fluoridated corticosteroid, one of the most potent available. Surgeons or dermatologist generally use this. As with any steroid, it can cause thinning, atrophy, easy bruising of the skin. Caution, stay away from face and neck.