Keratinization index.

A method to decrease subjectivity in assessing hyperkeratosis by application of quantitative measurements is proposed. The proportion of the depth of the stratum corneum to that of the total epidermis was measured on stained sections of tissue and termed the keratinization index (K.I.). Determinations showed that the K.I. varied with anatomical regions and was greater in different types of ichthyosis than in normal samples. Two indices were assessed, namely, K.I. which describes the ratio of cornified layer to total epidermis measured to the tips of the dermal papillae, and K.I. measured to the bases of the rete ridges. These two indices reflect the contour of the dermo-epidermal junction.