Pityriasis Rosea

  • Self-limited papulosquamous eruption; likely viral pathogen (human herpesvirus 7, less likely HHV 6)
  • Presents with initial herald patch (precedes eruption by 1–2 weeks) followed by salmon-colored oval patches and plaques with inner scale along long axis of Langer’s lines of cleavage (“Christmas tree” pattern on posterior trunk); variants include inverse pattern (flexural accentuation) and papular PR (young children and darker-skinned patients)