Pityriasis rosea

Background

  • Mild inflammatory exanthem
    • May be caused by HHV 6 and 7
    • 70% preceded by URI [1]
  • Most common 10-35yr old
  • Not contagious
  • Spontaneous resolution occurs within 4-12wk

Evaluation

Pityriasis rosea on back
Pityriasis rosea on front
Herald patch
  • Begins with single, "herald," patch (salmon-colored, fine scaling)
    • 1-2 weeks prior to generalized eruption
    • Larger lesion (Herald Patch) that resembles the later smaller lesions
      • Typically on the abdomen
  • Secondary maculopapular rash with plaques following Langer Lines ("Christmas tree" pattern)
    • Typically follows rip distribution
  • Pruritus can be moderate to severe
  • Consider RPR or VDRL to rule out syphilis

Differential Diagnosis

Rash

Management

  • Lasts 8 to 12 weeks[2]
  • Reassurance about the self-limited nature
  • Natural sunlight may speed up resolution
  • Pruritus[3]
    • Antihistamine, topical steroids
      • Triamcinolone 0.1% - Adults
      • Hydrocortisone 1% - children)
    • Other
      • Zinc oxide
      • Calamine lotion
    • Systemic steroids are generally not recommended.
  • Rash or pruritus beyond 12 weeks: reconsider original diagnosis
    • Consider biopsy to confirm the diagnosis

Disposition

  • Discharge

References

  1. Sharma PK, Yadav TP, Gautam RK, Taneja N, Satyanarayana L (2000). "Erythromycin in pityriasis rosea: A double-blind, placebo-controlled clinical trial". Journal of the American Academy of Dermatology 42 (2 Patient 1): 241–4. PMID 1064267
  2. Richard P. Usatine and Jennifer Krejci-Manwaring: Rakel: Textbook of Family Medicine, 8th ed., Saunders 2011, (Ch) 33:p720
  3. Richard P. Usatine and Jennifer Krejci-Manwaring: Rakel: Textbook of Family Medicine, 8th ed., Saunders 2011, (Ch) 33:p720