What disorder is characterised by an initial ‘herald patch’ which is then followed by scaly erythematous plaques usually in a ‘Christmas tree’ distribution?

Option A

Pityriasis rosea classically presents with a salmon coloured solitary patch ‘herald patch’ which enlarges over a few days followed by generalised bilateral and symmetric macules with collarette scale. Pruritus is sometimes present. It self resolves within 6 – 8 weeks.