parakeratosis

(pathology) Incomplete keratinization of epidermal cells characterized by retention of nuclei of cells attaining the level of the stratum corneum.

Disease of swine characterized by cessation of growth, erythema, seborrhoea, and hyperkeratosis of the skin; due to zinc deficiency and possibly to changes in essential fatty acid metabolism.

Persistence of nuclei in the stratum corneum of stratified squamous epithelium.

Retention of nuclei in the cells of the stratum corneum of the epidermis, as in psoriasis.

Persistence of the nuclei of keratinocytes as they rise into the horny layer of the skin; it occurs normally in the epithelium of the true mucous membrane of the mouth and vagina. When it occurs on the external skin it constitutes a lesion. The appearance is of thickening of the skin with thick scale formation, cracking and fissuring, and an underlying raw red surface. Occurs as a specific disease in pigs fed on rations deficient in zinc; the effect is exacerbated on diets high in calcium.

• inherited p. — occurs in calves, which are normal at birth but develop parakeratosis all over the body, especially on the legs and die after a long illness. Responds to treatment with zinc given orally. See also thymic hypoplasia. Called also lethal trait A46, adema disease.
• ruminal p. — the ruminal papillae are enlarged, leathery and adhered in clumps. The lesion is most severe in the dorsal part of the sac. Occurs principally in animals fed pelleted feed.