Atypical presentations of pityriasis rosea: case presentations

Atypical cases of pityriasis rosea (PR) are fairly common and less readily recognized than typical eruptions. We present four patients for whom we believe atypical PR is the most likely diagnosis. A 33-year-old man had purpuric lesions bilaterally on the legs with classical rash on the trunk. A 28-year-old woman had intensely pruritic and urticarial lesions. A 10-year-old girl had hundreds of small papular lesions 1-3 mm in size. A pregnant woman aged 26 had oral haemorrhagic ulcers with classical PR eruption on her trunk. The oral ulcers erupted and remitted at the same time as the generalized eruption. We reviewed the literature and proposed a classification based on rash morphology, rash size, rash distribution, number of lesions, site of lesions, severity of symptoms and course of the eruption. We believe that it is difficult to make a clear division to define typical and atypical PR, and that it is important not to ascribe any unusual or atypical skin eruption with PR unless other dermatoses have been excluded.