Why do lupus patients get nose n mouth sores?

Autoantibodies: Autoimmune diseases like lupus result in autoantibodies that attack your own body in error rather than bacterial or viral pathogens which are supposed to be targeted.This form of attack will manifest itself as sores in mucosal tissues including the nose and mouth.The exact mechanism may be an attack on the mechanism that holds the skin to underlying tissues allowing it to peel away creating sores.

Only about 25% do: Oral lesions can precede or follow skin lesions in about 25% of those affected. The sores{lesions} consist of multiple white plaques with dark reddish-purple margins with possible ulceration.