Cutaneous lesions of lupus erythematosus can be classified into specific and nonspecific types. There are 3 main specific subtypes based on morphology and distribution, chronicity, association with systemic lupus erythematosus (SLE), and histologic features including location / depth of inflammatory infiltrate. They are as follows:

Acute cutaneous lupus erythematosus (ACLE)

• Transient cutaneous findings typified by malar erythema without scarring
• Strongly associated with systemic findings
• Inflammatory infiltrate seen in the superficial dermis on biopsy

Subacute cutaneous lupus erythematosus (SCLE)

• Photosensitive cutaneous eruption lasting longer than ACLE but without scarring
• 10%-15% of patients go on to have systemic findings
• Inflammatory infiltrate seen in the upper dermis on biopsy

Chronic cutaneous lupus erythematosus (CCLE)

• Often interchangeably used to refer to its most common variant, discoid lupus erythematosus (DLE), but also includes the less common variants lupus tumidus, lupus panniculitis, and chilblain lupus
• DLE presents with chronic discoid lesions with permanent disfiguring scars most often seen on the scalp, face, and ears
• 5%-15% of patients go on to develop systemic findings
• In DLE, significant inflammatory infiltrate seen in superficial and deep dermis as well as prominent involvement of the adnexa on biopsy

SCLE is characterized by annular plaques with raised borders and central clearing or papulosquamous lesions that are restricted to sun-exposed skin. The sides of the face, the lower neck, the upper trunk, and the extensor surfaces of the arms are the most commonly affected sites. Although scarring is not a characteristic finding, dyspigmentation is common sequelae.

While the etiology remains poorly understood, there is a strong association with anti-Ro/SSA antibodies and SCLE. It is hypothesized that a complex interplay between genetic proclivity and environmental influences leads to a perpetuated autoimmune response. In addition, specific HLA types (1, B8, DR3, DRw52, DQ1, DQ2, and DRw6) have been shown to be associated with this specific subtype of cutaneous lupus erythematosus. Risk factors for developing cutaneous lesions include sex (3:1 female-to-male ratio, especially during childbearing years) and ethnicity, with individuals of African descent demonstrating a higher incidence compared with individuals of Northern European descent. Epidemiologic studies have shown that people of Hispanic, Asian, African American, and African Caribbean descent have an increased incidence of lupus in addition to excess morbidity.

Of note, certain drugs such as antihypertensives (hydrochlorothiazide, calcium channel blockers, and angiotensin-converting enzyme [ACE] inhibitors), antifungals (terbinafine), nonsteroidal anti-inflammatory drugs (NSAIDs), proton pump inhibitors (omeprazole), and, more recently, various chemotherapeutic agents (such as paclitaxel) and tumor necrosis factor (TNF)-alpha antagonists have been reported to trigger SCLE. These drug-induced SCLE lesions run an unpredictable course, and they may not clear completely after discontinuing the offending drug.

Photosensitivity is a prominent feature. Approximately 50% of patients meet the American Rheumatism Association (ARA) criteria of SLE, largely based on laboratory values and mucocutaneous findings. However, the incidence of severe systemic involvement such as renal or central nervous system involvement is relatively low in this population of lupus patients. About 10% of patients can develop acute cutaneous lupus or lesions of discoid lupus (chronic cutaneous lupus). In addition, anti-Ro/SSA antibodies are also seen in Sjögren syndrome, and some patients can have both SCLE and Sjögren syndrome.

The presence of erythema multiforme-like lesions in a patient with lupus, along with a speckled pattern of antinuclear antibody (ANA), positive anti-Ro/SSA or anti-La/SSB, and positive rheumatoid factor (RF) is known as Rowell syndrome. This syndrome has been described in patients with DLE, SCLE, and SLE. Its existence as a distinct entity has been debated in the literature; some authors believe the association is coincidental. Prednisone with or without hydroxychloroquine, dapsone, or immunosuppressive drugs such as cyclosporin have been cited as therapy.