Wind mass is a localized central edematous mass protruding on the surface of skin and mucosa, which is caused by the expansion and permeability increase of small blood vessels in skin and mucosa caused by mast cell activation. There is a reactive blush around, which usually disappears within 24 hours, but the rash can recur.
Vascular edema is characterized by sudden swelling of deep dermis, subcutaneous and mucous membrane with red or skin color, pain rather than itching, which subsides slower than wheal. Except for a few cases complicated with respiratory tract or other systemic symptoms, most of them have a good prognosis.