Cutaneous Lupus Erythematosus (CLE) is a chronic, inflammatory autoimmune disease that specifically targets the skin. The body’s immune system mistakenly attacks healthy skin cells, leading to visible lesions and rashes. The disease often follows a relapsing and remitting course, with symptoms flaring up and subsiding over time.
Defining Cutaneous Lupus Erythematosus
CLE is characterized by an autoimmune response where autoantibodies attack components within the skin, particularly at the junction between the epidermis and the dermis. This attack causes inflammation and damage, resulting in distinct skin lesions. The underlying pathology involves interface dermatitis, where immune cells infiltrate and cause the death of keratinocytes, the main cells of the outer skin layer.
CLE is a form of lupus, but it differs from Systemic Lupus Erythematosus (SLE), which affects internal organs. While CLE is confined to the skin, up to 75% of people with SLE develop skin manifestations. Conversely, the majority of patients initially diagnosed with CLE will not progress to the more severe, systemic form of the disease.
The likelihood of developing SLE varies significantly across CLE subtypes. Approximately 50% of people with the subacute form may have a mild systemic presentation, while only about 10% of those with the chronic, discoid form meet the criteria for SLE. The primary concern with CLE remains the potential for scarring and disfigurement.
The Three Primary Forms of CLE
Cutaneous Lupus Erythematosus is categorized into three major classifications based on lesion appearance, location, and potential for scarring. These distinctions guide prognosis and treatment strategies. The three main types are Acute Cutaneous Lupus Erythematosus (ACLE), Subacute Cutaneous Lupus Erythematosus (SCLE), and Chronic Cutaneous Lupus Erythematosus (CCLE), which commonly includes Discoid Lupus Erythematosus (DLE).
Acute Cutaneous Lupus Erythematosus (ACLE)
Acute Cutaneous Lupus Erythematosus (ACLE) is strongly associated with active systemic disease, meaning a person with ACLE is highly likely to have SLE. The most recognizable presentation is the malar rash, or “butterfly rash,” appearing as fixed redness across the cheeks and nose, typically sparing the creases next to the nostrils. This rash is usually transient, lasting days to weeks, and resolves without permanent scarring.
Subacute Cutaneous Lupus Erythematosus (SCLE)
Subacute Cutaneous Lupus Erythematosus (SCLE) is characterized by highly photosensitive, non-scarring lesions that favor sun-exposed areas like the upper back, chest, and arms, often sparing the face. These skin changes typically appear in two patterns: annular (ring-shaped) plaques with central clearing, or papulosquamous lesions resembling psoriasis. SCLE lesions heal without atrophy but can leave behind noticeable areas of altered skin color, known as dyspigmentation.
Chronic Cutaneous Lupus Erythematosus (CCLE)
Chronic Cutaneous Lupus Erythematosus (CCLE) is primarily represented by Discoid Lupus Erythematosus (DLE), which produces the most destructive skin lesions. These distinct, coin-shaped (discoid), violaceous-to-red plaques frequently develop on the face, scalp, and external ears. The chronic nature of DLE leads to permanent skin changes, including atrophy, central depigmentation, and significant scarring. When DLE occurs on the scalp, the destruction of hair follicles causes irreversible hair loss.
Causes and Environmental Triggers
The development of CLE is multifactorial, arising from a complex interplay between genetic susceptibility and environmental factors. While no single cause has been identified, certain genetic variations increase the risk of developing the condition. These predispositions set the stage for an overactive immune response to external stimuli.
Ultraviolet (UV) light exposure, particularly from the sun, is the most significant environmental trigger for CLE. UV radiation damages skin cells, causing them to release internal contents that the immune system mistakenly recognizes as foreign. This process initiates the autoimmune cascade, leading to the formation of lupus lesions or triggering a flare-up.
Other environmental factors contribute to the onset or exacerbation of CLE. Smoking is strongly associated with increased risk and severity, and it can interfere with treatment effectiveness. Certain medications, viral infections, and high levels of psychological or physical stress have also been implicated as triggers for CLE flares.
Diagnosis and Management Approaches
Diagnosing CLE relies on a combination of clinical evaluation and laboratory testing, as no single test is definitive. A physician performs a thorough physical examination, focusing on the appearance and distribution of skin lesions, particularly in sun-exposed areas. A skin biopsy of an active lesion is often performed to confirm the diagnosis, revealing the specific inflammatory pattern characteristic of lupus.
Blood tests are conducted to check for autoantibodies and rule out systemic disease. The presence of antinuclear antibodies (ANA) or anti-dsDNA antibodies can suggest the coexistence of SLE. The overall diagnostic picture is achieved by correlating physical findings, biopsy results, and serological test results.
Management of CLE focuses on controlling inflammation, preventing new lesions, and minimizing scarring and disfigurement. Strict sun protection is the foundational step in any treatment plan, as UV exposure is a primary trigger. This includes consistent use of broad-spectrum sunscreen, wearing protective clothing, and avoiding peak sun hours.
For localized or mild lesions, first-line therapy involves topical treatments such as high-potency corticosteroid creams or ointments, which suppress the local immune response. Topical calcineurin inhibitors are an alternative, particularly for facial lesions where long-term steroid use is a concern. When the disease is widespread, severe, or resistant to topical agents, systemic treatment is necessary. Antimalarial medications, such as hydroxychloroquine, are the primary systemic therapy for all forms of CLE, modulating the immune system and reducing inflammation.