Chronic eczema, habit reversal and natural healing
Over fifty years ago experiments with artificial scratching machines on normal skin showed how regular friction on the skin causes lichenification: the rough, dry and thickened skin seen in chronic eczema.
Instead of the regular, tightly packed appearance (a) of healthy skin, under the microscope chronic eczema shows marked variations in thickness of the epidermis (b), with a thickened surface layer (c), areas of separation between cells (d) and overactivity of cells of the basal layer (e).
What was also shown was that when the scratching machine was removed, the skin condition gradually returns to normal, a process that takes 28 days.
This is the length of time it takes for the dividing basal cells of the epidermis (f) to migrate steadily upwards to the surface (g). There is normally a steady turn-over of epidermal cells: as dead cells flake off the surface they are replaced by cells moving up from below.
This is the natural healing process that is released by habit reversal in The Combined Approach.
Goldblum, R.W. & Piper, W.N. (1954) Artificial lichenification produced by a scratching machine
Journal of Investigative Dermatology 22, 405-445