Lupus erythematosus: Significance of dermatologic findings

Herein, the different skin manifestations in patients with lupus erythematosus are reviewed, and their diagnostic, pathogenic and prognostic relevance are discussed, as well as their impact on therapeutic choices. The so-called specific lesions of LE result from an autoimmune pathomechanism and they allow diagnosis of LE by simple clinicopathological correlation since the findings are characteristic. They include the classic acute, subacute and chronic variants, characterised microscopically by interface dermatitis; the dermal variants of lupus, such as tumid lupus, displaying dermal perivascular lymphocytic infiltrate with mucin deposition under the microscope, and lupus profundus, in which lymphocytic lobular panniculitis progressing to hyaline fibrosis is found. Antimalarials are the treatment of choice for patients with specific LE lesions. The presence of some dermatological signs is the result of thrombotic vasculopathy. Their recognition allows the identification of lupus patients at increased cardiovascular risk and with a worse overall prognosis. Those signs include reticulated erythema on the tip of the toes, splinter hemorrhages, atrophie blanche, pseudo-Degos lesions, racemosa-type livedo, anetoderma, ulceration and necrosis. Those clinical manifestations, often subtle, must be recognised, and if present, patients should be treated with antiplatelet drugs. Finally, neutrophilic cutaneous lupus erythematosus includes a few entities that suggest that autoinflammatory mechanisms might play a key role in certain lupus manifestations. Among those entities, it is very important to diagnose neutrophilic urticarial dermatosis, which can mimic a classic lupus flare, because it is characterised by rash with joint pain, but immunosuppressants are not helpful. Dapsone is the treatment of choice.