Summary
Definition
Pityriasis rosea (PR) is an inflammatory skin condition of uncertain etiology, although an unknown infectious agent has been suggested. PR manifests as an acute, self-limited, inflammatory eruption characterized by a single larger lesion, the herald patch, followed by eruption of smaller papulosquamous oval lesions.
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Herald patch in classic distribution on the upper torso
From the collection of Daniela Kroshinsky, MD, MPH; used with permission
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[Figure caption and citation for the preceding image starts]:
Close-up herald patch
From the collection of Daniela Kroshinsky, MD, MPH; used with permission
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History and exam
Key diagnostic factors
- herald patch
- pruritus
- age 10 to 35 years
- 2- to 12-week duration
- scale
- located on trunk and upper extremities
- fir-tree pattern distribution
- located on face, palms, soles, mucosa
- acute to subacute recurrent skin eruption
Other diagnostic factors
- 2-week timing between herald patch and new lesions
- female sex
- prodromal symptoms
- pigmentary alteration (severe cases/dark skin color)
Diagnostic investigations
Investigations to consider
- skin biopsy
- antistreptolysin O titers
- potassium hydroxide (KOH) prep microscopy or fungal culture
- rapid plasma reagin/Venereal Disease Research Laboratory
Treatment algorithm
Contributors
Authors VIEW ALL
Director of Inpatient Dermatology
Associate Professor of Dermatology
Massachusetts General Hospital
Harvard School of Medicine
Boston
MA
Disclosures
DK declares that she has no competing interests.
Peer reviewers VIEW ALL
Chief of Dermatology
Brookdale Hospital
Brooklyn
NY
Disclosures
EL declares that she has no competing interests.
Fellow
Dermatology
University of Michigan
Ann Arbor
MI
Disclosures
LS declares that he has no competing interests.
Consultant Dermatologist
Department of Dermatology
Queen's Medical Centre
Nottingham University Hospitals NHS Trust
Nottingham
UK
Disclosures
JE declares that he has no competing interests.
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