Skin disease in cutaneous lupus erythematosus

Skin lesions in patients with systemic lupus erythematosus can be subdivided into lupus-specific (i.e., cutaneous lupus erythematosus [CLE]) and lupus-nonspecific categories. Researchers proposed three main categories of CLE (acute, subacute, and chronic), which can be distinguished based on their clinical presentations and disease courses. Acute CLE is often transient and favors sun-exposed areas, most commonly the face. Subacute CLE lesions linger longer than acute CLE and present in photoexposed sites such as the upper trunk and extremities. Medications can account for up to one-third of patients with subacute CLE. Chronic CLE contains the largest number of subtypes with multiple different manifestations such as scarring and dyspigmentation (discoid lupus erythematosus), arcuate plaques (tumid LE), and indurated subcutaneous plaques (LE panniculitis). Most CLE subtypes share similar pathologic features including scattered dyskeratotic keratinocytes, interface dermatitis, perivascular and perifollicular inflammatory infiltrates, and increased mucin deposition. Lupus-nonspecific skin lesions, which lack these previously mentioned histologic findings, are usually present in patients with SLE as well as other autoimmune diseases, such as dermatomyositis and scleroderma. Some have served as classification criteria for SLE, whereas others result in severe disease sequelae such as vasculitis and vasculopathy. Recognition of the various skin presentations that are associated with lupus can help facilitate diagnosis and hasten appropriate treatments for these patients.