Pityriasis Rosea
- Cause is unknown.
- Viral agent HHV-7 is implicated.
- Not contagious.
- Common in winter.
- Affects young adults and children.
Clinical
starting with single lesion oval/erythametous, salmon light brow / plaque or patch front or back of trunk; Mother patch/herald patch
after few days eruption of other lesions fine scaly macule papules on trunk
-
Generalized eruptions is preceded by an ‘herald patch’or ‘mother patch’.
-
The patch is larger, redder, more scaly and rounder than the later lesions.
-
Is itchy and run along the rib lines.
-
The skin lesions resemble an ‘christmas tree’
Herald Patch
Prognosis
-
Is a self limiting skin lesion that last 2-10 wks
-
Resolves leaving hyperpigmented patches.
Differential Diagnosis
- Guttate psoriasis
- Tinea corporis
- Pityriasis versicolor
Investigations
- VDRL → to exclude syphilis
- Microscopic examination of scales to role out tinea corporis & pityriasis versicolor.
Treatment
- No treatment
- reassurance
- But in severe cases we can give:
- Steroid.
- Calamine lotion.
- 1% salicylic acid in white paraffin- to reduce scaling.