Pityriasis amiantacea

Pityriasis amiantacea (also known as "Tinea amiantacea") is an eczematous condition of the scalp resulting in hair loss in which thick tenaciously adherent scale infiltrates and surrounds the base of a group of scalp hairs.

Pityriasis amiantacea was first described by Alibert in 1832. Pityriasis amiantacea affects the scalp as shiny asbestos-like (amiantaceus) thick scales attached in layers to the hair shaft. The scales surround and bind down tufts of hair. The condition can be localised or covering over the entire scalp. Temporary alopecia and scarring alopecia may occur due to repeated removal of hairs attached to the scale. It is a rare disease with a female predilection.