Pityriasis

Pityriasis commonly refers to flaking (or scaling)¹ of the skin. The word comes from the Greek πίτυρον 'bran'.

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