Which autoimmune disease is characterized by a butterfly-shaped rash on the face?

The autoimmune disease characterized by a butterfly-shaped facial rash is systemic lupus erythematosus (SLE).

The rash is called a malar rash because it crosses the cheeks and bridge of the nose, often sparing the folds beside the nostrils. It may be red or purplish, mildly scaly, and worsened by sunlight. SLE is a systemic autoimmune disease in which the immune system can attack skin, joints, kidneys, blood cells, the nervous system, and other tissues.

The butterfly rash is a classic clue, but it is not present in every person with lupus and is not unique to SLE. Similar facial rashes can occur with dermatomyositis, pellagra, rosacea, and Bloom syndrome. Conversely, a rash alone cannot establish a lupus diagnosis; clinicians combine examination findings with medical history and laboratory testing.

“Lupus” means wolf in Latin, a historical reference to certain facial lesions. SLE is also distinct from cutaneous lupus, which may primarily affect the skin without the broader organ involvement associated with systemic disease.