Ruey J. Yu

Metabolic Basis for Disturbed Keratinization in Ichthyosis and Other Diseases

Molecular structures of therapeutic agents now known to normalize disturbed keratinization in ichthyosis and other disorders of keratinization suggest that keratinization is normally modulated by certain α-hydroxy or α-keto acids. Evidence for this includes the demonstrated efficacy of topically applied α-hydroxy and α-keto acids in ichthyosis; the presence of ichthyotic skin in Refsum’s disease, a disorder associated with failure of an α-hydroxylase; and preliminary findings that active forms of vitamin A acid may be hydroxylated derivatives.

Alpha hydroxy acids. Procedures for use in clinical practice

Alpha hydroxy acids and alpha keto acids applied topically in lower concentrations reduce the thickness of hyperkeratotic stratum corneum by reducing corneocyte cohesion at lower levels of the stratum corneum. This property permits efficient clinical control of dry skin, ichthyosis, follicular hyperkeratosis, and other conditions characterized by retention of stratum corneum. Applied topically in higher concentrations, these acids cause epidermolysis. This property provides a new alternative for treating seborrheic keratoses, keratoses commonly known as age spots, actinic keratoses, and verrucae vulgares; all of which lesions involve distinct epidermal hyperplasia as well as retention of stratum corneum. Facial wrinkles can be modified with topical alpha hydroxy acids, applied in higher concentrations as office procedures, and concomitant daily home application of lower concentrations.