Image Based Question-64954

A 16 year old boy presented with asymptomatic, multiple erythamatous annular lesions with a collarette of scales at periph-ery of the lesions present on the trunk. The most likely diagnosis is?

A. Pityriasis versicolor

B. Pityriasis alba

C. Pityriasis rosea

D. Pityriasis rubra pilaris

Correct Answer » C Explanation

Ans:C.)Pityriasis Rosea.

Pityriasis rosea is a self limiting disorder of unknown etiology, with a suspected association with Herpes virus 7 and 6.

• It presents with development of usually asymptomatic (i.e. no prodromal or constitutional system), sharply (well) demarcated, larger (2-6 cm), annular (oval-round), erythematous (red to brown) lesion k/a primary/herald/mother patch mostly located on trunk in children and young adults (10-35 yrs).
•  Similar but smaller secondary eruptions appear in crops at interval of usually 2 weeks distributed along lines of cleavage in christmas (fir) tree appearance. 
• Lesions demonstrate fine (cigarette paper) collarette of scaleQ] just inside the peripheray of plaque.