Lupus vulgaris is an extremely chronic tuberculous affliction of the skin and mucous membranes, characterized by the presence of nodules which either ulcerate or resolve with the formation of scar tissue. The elementary lesions are soft, brownish, pin-head to pea-sized tubercles which at first do not project above the level of the skin. Looked at through a glass slide pressed firmly down upon them, the nodules have exactly the color and appearance of apple jelly. They may remain unchanged for months or by growth and coalescence develop into large patches or nodes. Resolution occurs with crusting and final scarring. The scars are usually fibrous, puckered and disfiguring, and often contain new tubercles in their substance.