Ans. is 'd' i.e., 6-12 weeks * P. rosea is self limiting disease, subsides with 6-12 weeks.Pityriasis rosea* P. rosea is a common scaly disorder, occuring usually in children and young adults (10-35 years). Characterized by round/oval pink brown patches with a superficial, centrifugal scale, distributed over trunk in a Christmas tree pattern. The exact etiology is not known, but it is considered to be a viral disease; Human Herpes virus 6 (HHV 6) and Human Herpes virus 7 (HHV 7) may play a role.Clinical manifestations of P. rosea* The disease starts with an upper respiratory prodrome or a mild flu. After 1-2 weeks, annular erythematous plaque appears on trunk that is referred to as mother patch or herald patch. Over the next 1-2 weeks, fresh patch appear all over the trunk, in a Christmas tree configuration or Fir tree Configuration. The lesions are pinkish in white skin, hence the name rosea. However, on the dark Indian skin the lesions are skin coloured or brown. The most characteristic clue for the diagnosis is the presence of a fine scale at the edge of the lesion referrred to as centrifugal scale or collarette scales or cigarette paper scales. Lesions subside with hyperpigmentation. Trunk is involved predominantly, Sometimes (in 20% of patients) lesions occur predominantly on extremities and neck (inverse pattern).* Hanging curtain sign is seen in patients with pityriasis rosea. When the skin is stretched across long axis of herald patch, the scale is noted to be finer, lighter, and attached to one end, which tends to fold across the line of scratch