Accumulating evidence suggests that IgE-independent activation of mast cells should play a critical role in a wide variety of cutaneous inflammatory diseases; about 20% of patients with atopic dermatitis were reported to have no IgE-sensitization to environmental antigens and low serum IgE levels (intrinsic atopic dermatitis) [8], and about 50% of patients with chronic urticaria were found to spontaneously develop the symptoms [9]. This evidence concerns the gene IGHE and atopic eczema.