Hyperkeratosis Parakeratosis Hyperparakeratosis UMLS:C1265968 Histological term to illustrate the combined presence of parakeratosis and hyperkeratosis. Abnormal keratinization of the epidermal stratum corneum (horny layer) with increased keratin formation and preservation of the nuclei in the superficial cells. Parahyperkeratosis SNOMEDCT_US:125554003 Parakeratotic hyperkeratosis