Pityriasis rosea; Pityriasis circinata; Pityriasis maculata

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Etiology

Epidemiology

  • moderately common
  • worldwide distribution
  • all races affected
  • peak incidences in spring & autumn in temperate zones
  • females affected slightly more than males
  • most patients are 10-43 years of age

Pathology

* histopathology image[6]

Clinical manifestations

  • self-limited condition lasting 4-8 weeks (1-3 months[1])
  • occasional mild 'viral syndrome-like' prodrome
  • mild pruritus
  • herald patch (primary lesion)
    • single, round or oval (annular) erythematous to salmon-colored patch 2-6 cm in diameter with a peripheral rim of scale
    • generally occurs on the trunk (Christmas tree pattern)
    • precedes the macular papular lesions by 2-21 days
  • secondary lesions
    • macules or papules involving the trunk, less frequently the extremities, scalp & face
    • lesions are usually oval & follow the crease lines (Langer lines) of the skin
    • 0.5-1.5 cm in diameter
    • lesions appear in crops, adopts 'Christmas tree' pattern on trunk
    • distribution mainly on torso, but may affect proximal extremities
    • lesions may continue to appear for 2-3 weeks
    • complete resolution of rash in 6-14 weeks
  • recurrences are uncommon (3%)
  • involvement of internal organs does not occur

* images[5][6][7]

Laboratory

Differential diagnosis

Management

More general terms

References

  1. 1.0 1.1 1.2 1.3 1.4 Medical Knowledge Self Assessment Program (MKSAP) 15, 16, 17, 18. American College of Physicians, Philadelphia 2009, 2012, 2015, 2018.
    Medical Knowledge Self Assessment Program (MKSAP) 19 Board Basics. An Enhancement to MKSAP19. American College of Physicians, Philadelphia 2022
  2. Harrison's Principles of Internal Medicine, 13th ed. Companion Handbook, Isselbacher et al (eds), McGraw-Hill Inc. NY, 1995, pg 800
  3. Saunders Manual of Medical Practice, Rakel (ed), WB Saunders, Philadelphia, 1996, pg 950-51
  4. Browning JC. An update on pityriasis rosea and other similar childhood exanthems. Curr Opin Pediatr. 2009 Aug;21(4):481-5. PMID: https://www.ncbi.nlm.nih.gov/pubmed/19502983
  5. 5.0 5.1 Pityriasis rosea (image) American Academy of Dermatology https://www.aad.org/public/diseases/rashes/pityriasis-rosea
  6. 6.0 6.1 6.2 Schwartz RA, Elston DM (images) Medscape: Pityriasis Rosea http://emedicine.medscape.com/article/1107532-overview
  7. 7.0 7.1 Pityriasis rosea. Pityriasis rosea. (images) http://www.dermnetnz.org/viral/pityriasis-rosea.html
  8. Wollenberg A, Eames T. Skin diseases following a Christmas tree pattern. Clin Dermatol. 2011 Mar-Apr;29(2):189-94 PMID: https://www.ncbi.nlm.nih.gov/pubmed/21396559