Darriers sign seen in -

Ans. is 'b' i.e., Urticariapigmentosa o Urticaria pigmentosais a familial cutaneous disorder characterised by generalised distribution of red brown macules.o Each lesion represents a collection of mast cells in the dermis with hyperpigmentation of overlying epidermis,o The most characteristic features is that these lesions urticate on scratching.o Light scratching with the point of forceps or rounded tip of a pen or even rubbing causes these mast cells to degranulate leading to localized urticaria (become red swollen and enlarged) - Darrier's Signo Extensive release of histamine from mast cell degranulation may result in - Headache, flushing diarrhea and pruritis.