Parakeratosis is
Normally nucleus will be lost in keratinocytes when they reach stratum corneum.
Presence of nucleated keratinocytes in stratum corneum is seen in psoriasis because of decrease in transit time - termed as " parakeratosis"
Premature and abnormal keratinization
Increased formation of keratin
Nucleated keratinocytes in stratum corneum
Elongated rete ridges