Welt

A red bump, ridge or swelling of unbroken skin raised by a stinging blow or by an allergic reaction to foods, drugs or insect bites, as in hives (urticaria).

The word “welt” has a number of nonmedical but related meanings including: in sewing, an edge of cloth folded on itself, often over a cord, and sewed down; and in shoemaking, a narrow strip of leather around the shoe between the upper leather and sole.