All are true statements regarding us, EXCEPT:
It is characterised by yellowish cup shaped crests called scutula. Dark brown/black nodules are seen as black piedra caused by piedraia hoae.Ref: Rook's Textbook of Dermatology, 8th Edition
It is a form of Tinea capitis
It is caused by Tinea schoenlein
It causes cicatricial alopecia
It is characterised by presence of dark brown to black nodules cemented to the hair shaft