Darier's sign is seen in: . (AIIMS Nov 2014)
1). Mastocytosis is a relatively uncommon disease, characterized by abnormal accumulation of mast cells in skin and / or other organs.
2). The disease can manifest at any time from infancy to middle age with a variety of cutaneous manifestations.
3). The most common manifestation seen in 65% of cases is called urticaria pigmentosa which starts during infancy and consists of multiple, irregular, hyperpigmented macules on trunk and extremities.
4). Mast cells degranulate by, stimuli such as rubbing or heat and this leads to the formation of localized urticaria (Darier's sign).