pityriasis

Pityriasis commonly refers to flaking (or scaling) of the skin. The word comes from the Greek πίτυρον 'bran'.

==Classification== Types include: Pityriasis alba, dry, fine-scaled, pale patches on the face Pityriasis lichenoides chronica, caused by a hypersensitivity reaction to infectious agents Pityriasis lichenoides et varioliformis acuta, a disease of the immune system Pityriasis rosea, a type of skin rash Pityriasis circinata, Pityriasis rubra pilaris, reddish-orange patches (Latin: rubra) on the skin Pityriasis versicolor, a skin eruption on the trunk and proximal extremities, usually caused by a fungus Dandruff, historically called Pityriasis capitis Pityriasis amiantacea, condition of the scalp in which thick tenaciously adherent scale infiltrates and surrounds the base of a group of scalp hairs