Cutaneous lupus erythematosus (CLE) is an autoimmune condition that primarily affects the skin, causing a range of rashes and lesions. The body’s immune system mistakenly attacks its own skin cells, leading to inflammation. CLE is distinct from systemic lupus erythematosus (SLE), which affects internal organs, though an association can exist. Symptoms may appear suddenly and disappear, or persist indefinitely, often manifesting as a red, scaly rash, frequently triggered by sun exposure.
Forms of Cutaneous Lupus Erythematosus
Cutaneous lupus erythematosus is categorized into several forms, each with distinct characteristics and presentations on the skin.
Chronic Cutaneous Lupus Erythematosus (CCLE)
Chronic Cutaneous Lupus Erythematosus (CCLE), with discoid lupus erythematosus (DLE) being the most common type, typically presents as coin-shaped, thick, raised, and scaly patches. These lesions are often pink and may flake or form a crust on the skin’s surface. DLE commonly appears on sun-exposed areas such as the scalp, ears, cheeks, nose, and lips, and can lead to permanent hair loss if it affects the scalp. These lesions heal slowly, often leaving behind areas of lighter or darker skin pigmentation and scarring.
Subacute Cutaneous Lupus Erythematosus (SCLE)
Subacute Cutaneous Lupus Erythematosus (SCLE) is characterized by non-scarring, sun-sensitive rashes. The lesions often appear in sun-exposed areas like the upper back, shoulders, arms, neck, and upper torso, while the face may be spared. These rashes can manifest as annular (ring-shaped) lesions or as papulosquamous (psoriasis-like) lesions. SCLE lesions heal without scarring, though they may result in noticeable changes in skin pigmentation.
Acute Cutaneous Lupus Erythematosus (ACLE)
Acute Cutaneous Lupus Erythematosus (ACLE) is often associated with active systemic lupus erythematosus and presents as a transient rash. The most recognizable form is a butterfly-shaped rash, also known as a malar rash, which spreads across the nose and cheeks. This rash is flat, red, and may resemble a sunburn, though it usually does not hurt but can itch. Rashes may also appear on other areas, such as the arms or legs, and are frequently triggered by sun exposure.
Recognizing Cutaneous Lupus Erythematosus
Recognizing cutaneous lupus erythematosus involves observing specific skin changes and associated discomfort. The skin lesions often appear as red or purplish patches, which can be scaly or thickened. These rashes are frequently found in areas exposed to the sun, including the face, scalp, chest, and arms.
Patients may experience itching or pain in the affected areas. Photosensitivity is a common symptom, where skin reactions worsen or are triggered by sun exposure. Beyond visible rashes, individuals might notice hair loss, particularly if the scalp is affected by discoid lesions. These lesions can also result in permanent scarring or alterations in skin pigmentation.
Diagnosis and Management
Diagnosing cutaneous lupus erythematosus involves clinical examination, laboratory, and pathological tests. A dermatologist will assess the skin lesions and review the patient’s medical history. Blood tests are performed to check for specific antibodies, such as antinuclear antibodies (ANA), anti-Ro/SSA, and anti-La/SSB, which can indicate an autoimmune response.
A skin biopsy is often performed, where a small tissue sample from an affected area is taken for microscopic analysis that can reveal characteristic changes associated with lupus. Direct immunofluorescence may also be performed on the biopsy sample to detect immune deposits in the skin.
The management of CLE focuses on reducing inflammation, preventing scarring, and alleviating symptoms. Topical therapies are often the first line of treatment, including corticosteroids like clobetasol or triamcinolone, which help to reduce inflammation directly on the skin. Calcineurin inhibitors, such as tacrolimus and pimecrolimus, are also used topically to suppress the immune response in the skin.
For more widespread or severe cases, systemic medications may be prescribed. Antimalarial drugs, such as hydroxychloroquine or chloroquine, are frequently used due to their anti-inflammatory properties. Oral corticosteroids may be used for short periods to control severe flares, while immunosuppressants like methotrexate or azathioprine can be considered for persistent or resistant cases. Alongside medical treatments, strict sun protection is essential, involving the regular use of high-SPF sunscreens, wearing protective clothing, and avoiding sun exposure during peak hours.
Relationship to Systemic Lupus Erythematosus
Cutaneous lupus erythematosus and systemic lupus erythematosus are distinct conditions, but they can be related. While CLE primarily affects the skin, some individuals with CLE may either develop or already have SLE, which involves inflammation and damage to internal organs and joints. The presence of skin symptoms can sometimes be the first indication of SLE.
The likelihood of CLE progressing to SLE varies depending on the specific form of cutaneous lupus. Discoid lupus erythematosus (DLE) rarely progresses to SLE, with only about 1–2% of patients with localized DLE developing systemic disease. In contrast, acute cutaneous lupus erythematosus (ACLE) is almost always associated with active SLE. Subacute cutaneous lupus erythematosus (SCLE) carries an intermediate risk, with approximately half of SCLE patients meeting criteria for SLE classification, though their systemic disease is generally mild, often presenting with joint or muscle pain. Given this potential connection, monitoring for systemic symptoms is an important aspect of ongoing care for individuals diagnosed with CLE.