Cutaneous lupus erythematosus (CLE) is the term doctors use when a disease called lupus erythematosus affects the skin. About two-thirds of patients with lupus will develop CLE. Many patients with CLE also have other organs, such as the heart, lungs, kidneys, muscles, and joints, affected by lupus.
Lupus erythematosus is an autoimmune disease resulting in increased inflammation throughout the body. The inflammation, or damage, can be caused directly by immune cells or specialized proteins called antibodies produced by immune cells. In most patients with lupus, the immune system makes anti-nuclear antibodies (ANA), which are given this term because they stick to the nucleus of normal cells.
Lupus erythematosus is caused by genetic, environmental, and immune system factors, leading to increased inflammation.
Cutaneous lupus erythematosus (CLE) can present with a broad range of skin lesions. Doctors divide these skin lesions into three categories or types: acute, subacute, and chronic or discoid.
Acute CLE often presents as a red rash on the cheeks and nose called a “butterfly rash.” Most patients with acute CLE eventually develop lupus in other parts of the body.
Subacute CLE most often presents as a red, raised, scaly rash on sun-exposed areas of the body. Skin lesions are ring-like and may look similar to psoriasis or eczema. Approximately 10-15% of patients with this form of CLE eventually develop lupus in other parts of the body.
Chronic or discoid CLE often starts with a red, round, scaly rash on the scalp, face, ears, and other sun-exposed areas. Skin lesions may heal but leave discolored scars and hair loss on the scalp. Approximately 5-10% of patients with this form eventually develop lupus in other parts of the body.
The diagnosis of CLE requires information from various sources, including your medical history, a physical examination, blood tests, and a skin biopsy. Your medical team will work collaboratively to gather and share this information to determine the correct diagnosis.
A skin biopsy is a procedure in which a small sample of tissue is removed and sent to a pathologist for examination under a microscope. The sample can be used to look for inflammation, tissue damage, and abnormal antibodies in the skin.
Common microscopic features of cutaneous lupus erythematosus include:
Direct immunofluorescence (DIF) is a test that pathologists perform to look for specific proteins in a tissue sample. Unlike most tissue samples, which are examined using normal light, DIF tissue samples are examined using fluorescent light. This makes it easier for your pathologist to see abnormal proteins in the sample. In patients with CLE, tissue samples analyzed by DIF will often show increased amounts of immune system-related proteins in the area of the basement membrane. These proteins include IgG, IgM, IgA, and C3.