Acanthosis

From the Greek derived from "akantha" (sting). Widening of the stratum spinosum usually by proliferation (hyperplasia) of the cells of the stratum spinosum, lengthening of the reteleiste, possibly also by individual enlargement (hypertrophy) of the keratinocytes. Depending on the kinetics, a distinction is made between retention acanthosis and proliferation acanthosis. Acanthosis is found in ichthyosis, psoriasis and psoriasiform dermatoses such as pityriasis rubra pilaris, chronic eczema and lichen planus.