Pityriasis rosea
Lianjun Chen
Huashan Hospital
Definition
• an acute, self-limited skin disease
• characterized by the presence of
 rosy-coloured
round to oval macular lesions
 with a rim of fine scales
• appear most common in crops on the trunks and
proximal extremities.
Epidemiology
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Most cases of pityriasis rosea occur in young healthy
persons, the majority of whom are between the ages of 10
and 35 years.
Its peak incidence is during adolescence, and it is rarely
diagnosed before the age of 2 years.
There is no racial predilection and it is found worldwide.
There is a slight female predominance, and some studies
have even suggested a female : male ratio of 2 : 1.
The typical eruption lasts 6 to 8 weeks, though
exceptionally it can persist for 5 months or longer.
Some authors report a modest seasonal variation with
peaks in the spring and fall.
Etiology and Pathogenesis
 The etiology is unknown.
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A viral etiology is frequently proposed.
There is some evidence implicating HHV6 &7 infection
in the pathogenesis .
Clinical Manifestation
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Predominantly seen in adolescents and young
adults during spring and fall.
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Occur mostly on the trunks and proximal
extremities.
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Lasting for about 6-8 weeks or longer.
Self-limited. Recurrences are regarded as
unusual.
Clinical Manifestation
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The initial lesion is frequently a single, 2-5cm or
bigger round plaque,names as “Herald patch”.
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Within several days, smaller oval maculars appear,
with a wrinkled, salmon-colored central area and a
darker red peripheral zone with gyrate border
,separated by a collarette of fine scaling . The
lesions distribute with their long axis following
Langer's lines of cleavage.
Herald patch
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A self-limited papulosquamous eruption that
is occasionally pruritic
Seen primarily in adolescents and young
adults, favoring the trunk and proximal
extremities
Individual lesions are usually oval in shape
and their long axis is oriented along Langer's
lines of cleavage
Less common variants include inverse,
vesicular, purpuric and pustular
Differential Diagnosis
 Tinea corporis
 nummular dermatitis
 Psoriasis
 Syphillis
 Seborrheic dermatitis
 Drug eruption
Treatment
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Traditional Chinese medicine ：heat-clearing and
detoxicating
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Symptomatic treatment：antihistamines
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Topical corticosteroids
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Phototherapy
A
brief course of systemic corticosteroids(Rarely)