Pityriasis rosea

An inflammatory skin disease with unclear aetiology, although an infectious cause has been suggested.

Can present in patients of any age but most often in people aged 10 to 35 years.

Manifests as an acute, self-limiting, inflammatory eruption characterised by a single larger lesion, the herald patch, followed by eruption of smaller papulosquamous oval lesions.

Spontaneous resolution, usually over several weeks, but can persist for up to 5 months.

Symptoms treated by topical corticosteroids and/or oral antihistamines, or UV therapy.

Pityriasis rosea (PR) is an inflammatory skin condition of uncertain aetiology, although an unknown infectious agent has been suggested. PR manifests as an acute, self-limiting, inflammatory eruption characterised by a single larger lesion, the herald patch, followed by eruption of smaller papulosquamous oval lesions. [Figure caption and citation for the preceding image starts]: Herald patch in classic distribution on the upper torsoFrom the collection of Daniela Kroshinsky, MD, MPH; used with permission [Citation ends].[Figure caption and citation for the preceding image starts]: Close-up herald patchFrom the collection of Daniela Kroshinsky, MD, MPH; used with permission [Citation ends].