Features of psoriatic alopecia:
(1) The alopecia may be localized or diffuse. It tends to occur in areas involved by psoriatic skin lesions.
(2) It may occur as an acute or chronic condition. During acute hair loss many hairs are in telogen. Some patients develop a scarring alopecia with permanent hair loss.
(3) It may be limited to the scalp or affect other areas of body hair.
(4) Other causes of alopecia (androgenetic, fungal, drug, etc) are excluded.
(5) Hair may regrow with anti-psoriatic therapy, unless the patient has developed a scarring alopecia.
Skin biopsies may show progression from:
(1) a chronic perifollicular inflammatory cell infiltrate to
(2) granulomatous inflammation with foreign body type giants cells to
(3) loss of hair follicles with fibrosis
