temperature may lead to mast cell destabilization and histamine release Refer to www.mastokids.org for more information about common mast cell degranulation triggers Blistering of such lesions generally occurs in the first few years of life After this time, urticaria occurs more often than blistering Lesions may be generalized and are often associated with more severe cutaneous disease or rarely systemic mastocytosis When a presumed melanocytic lesion feels infiltrated, the physician should think of mastocytosis—Darier sign will confirm the diagnosis If asymptomatic and localized, active nonintervention is appropriate For symptomatic disease, primary treatment is aimed at preventing histamine release with H1 and H2 antihistamines The majority of patients have regression over time FIGURE 67.1 Blisters on hands of a child with scabies