Peripheral 'Collarette of scales' is a feature of:
Clinical features of Pityriasis rosea is the rash which consists of circular or oval pink macules with a 'collarette of scale' and is more prominent on the trunk than on the limbs. Ref: Kumar and Clark's Clinical Medicine by Parveen June Kumar, Michael L. Clark, Elsevier Saunders, 2005, Page 1335; Thieme Clinical Companions Dermatology By Wolfram Sterry, Walter Burgdorf, Ralf Paus, 2006, Pages 279-280
P. rosea
P.veriscolor
Lichen planus
Pityriasis rubra pilaris