Pityriasis rosea

•  mild, common, self-limited eruption; may be due to human herpesvirus 7 (HHV-7)
•  suspected infectious etiology due to: occurrence primarily in adolescents and young
   adults in the spring and fall; recurrence is uncommon

    

 

     

     

•  eruption typically evolves over 6-8 weeks
                  - development of herald "patch", a solitary 2-6 cm scaly plaque

     

     

•  eruption typically evolves over 6-8 weeks
                  - eruption of multiple 1-2 cm oval annular papules with fine "collarette"
                      scaling along the rim of individual lesions

     

     

     

    

•  eruption typically evolves over 6-8 weeks
                  - lesions typically located in a "T shirt and shorts" distribution
                  - pruritus is variable
•  pityriasis rosea can be mimicked by:
                  - secondary syphilis: if in any doubt, do a VDRL; you never want to miss a
                    case of syphilis
                  - drug eruptions: especially ACE inhibitors and gold
•  treatment is not usually necessary