The main purpose of occlusive dressing is to occlude the area of skin bearing the lesion from the outside atmosphere. Many diseases like intractable lichenified or hyperkeratotic lesions such as those seen in lichen simplex chronicus, hypertrophic lichen planus, psoriasis, keratodermas, etc. are better treated under occlusive dressing with corticosteroids.
The sweat and water released from this area keep on accumulating inside the occluded space, raise its humidity, produce maceration and damage the epidermal barrier. This helps in more efficient penetration of corticosteroids and a quicker regression of the lesion.
Occlusion is done by smearing the lesions liberally with a corticosteroid ointment and covering them with polyethylene sheets or tubing. When the lesions are situated on an extremity, these can be covered with polyethylene tubing and the upper and the lower ends sealed with adhesive tape.
In case a joint is to be enclosed in the occlusive dressing, the polyethylene tubing should be left sufficiently loose to allow free movements of the joint. If the lesions are situated on the trunk, one will have to use polyethylene sheets and seal all the four sides with adhesive tape.
For further protection, the polyethylene dressing may be covered with an ordinary bandage to prevent it from rupturing. This dressing has to be maintained till the humidity inside the occlusion usually takes three or four days, while in summer, even 24 hours may be enough.
When the dressing is removed at the end of this period, there is frequently a good deal of maceration and four smell. This should be washed with soap and water, the skin should be mopped dry and the occlusive dressing repeated after application of more corticosteroid ointment.
This procedure should be continued till the lesions have regressed completely. As a rule, significant improvement can be achieved in two weeks time.
Some patients cannot tolerate the occlusive dressing, because they develop pustular miliaria-like lesions. This happens more frequently in summer months.
In such cases, an ordinary bandage after local application of the corticosteroid ointment, applied after the bath and kept till the next bath, is quite helpful.
Some chemicals such as dimethylsulphoxide (DMSO) have the capacity to overcome the epidermal barrier and thus help the drug to penetrate the skin without resorting to intralesional injections or occlusive dressing.
DMSO is generally added in a concentration of 10-40 percent.
