Bullae are elevated, fluid-filled blisters ≥ 10 mm in diameter.
The autoimmune bullous diseases include
Although epidermolysis bullosa acquisita is thought to be an autoimmune disease, epidermolysis bullosa Epidermolysis Bullosa Epidermolysis bullosa is a group of 4 very rare genetic diseases and their subtypes. Epithelial fragility and easy blistering of skin and mucous membranes usually manifest at birth or in infancy... read more 
is a group of inherited diseases in which epithelial adhesion protein defects lead to epithelial fragility and bullae formation.
Other bullous conditions include staphylococcal scalded skin syndrome Staphylococcal Scalded Skin Syndrome Staphylococcal scalded skin syndrome is an acute epidermolysis caused by a staphylococcal toxin. Infants and children are most susceptible. Symptoms are widespread bullae with epidermal sloughing... read more 
, toxic epidermal necrolysis Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) Stevens-Johnson syndrome and toxic epidermal necrolysis are severe cutaneous hypersensitivity reactions. Drugs, especially sulfa drugs, antiseizure drugs, and antibiotics, are the most common... read more 
, severe cellulitis Cellulitis Cellulitis is acute bacterial infection of the skin and subcutaneous tissue most often caused by streptococci or staphylococci. Symptoms and signs are pain, warmth, rapidly spreading erythema... read more 
, and certain drug eruptions Drug Eruptions and Reactions Drugs can cause multiple skin eruptions and reactions. The most serious of these are discussed elsewhere in THE MANUAL and include Stevens-Johnson syndrome and toxic epidermal necrolysis, hypersensitivity... read more 
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