Case Presentation Extraordinarily long linear cutaneous lupus erythematosus along the lines of blaschko
Linear cutaneous lupus erythematosus (LCLE) is a rare subtype of cutaneous lupus erythematosus. We describe a 22-year-old Japanese man who had an 11-year history of asymptomatic linear erythema from the right upper back to the dorsum of the right hand. The lesions followed the lines of Blaschko and spread over three large joints. Histological findings were compatible with discoid lupus erythematosus. Although the most common site for LCLE is the face, a few cases of LCLE on the extremities have
... he extremities have been reported. To our knowledge, this is the first reported case of an extraordinarily long, continuous LCLE skin lesion. Case synopsis Linear cutaneous lupus erythematosus (LCLE) is a rare subtype of cutaneous lupus erythematosus. The term LCLE was proposed by Abe et al in 1998 . LCLE develops linear lesion following the lines of Blaschko, although its etiology remains unknown. Histological findings are compatible with discoid LE (DLE) according to previous reports [1-4]. We describe a case of LCLE, which was distributed as a long constitutive line that crossed three large joints. This Japanese man noted the disease onset in his childhood. Such long skin lesions of linear cutaneous LE strongly connects this disorder with the lines of Blaschko. A 22-year-old Japanese man presented with an 11-year history of asymptomatic linear erythema that had appeared on the right upper arm. The lesion expanded gradually to the right shoulder and the dorsum of the right hand. There was no history of trauma around the lesions, nor of intensive exposure to sunlight. He had neither photosensitivity nor family history of any skin disease. Scaly erythema with partly whitish atrophy were seen from the right upper back to the right hand (Fig. 1A-C). The lesions followed the lines of Blaschko  (Fig. 1D). Laboratory examination, including complete blood count, liver function test, blood urea nitrogen test, and urinalysis, showed no abnormalities. Anti-nuclear antibodies were positive with a homogeneous pattern (1:80). Other autoantibodies, including anti-SS-A, Sm, U1-RNP, ds-DNA, ss-DNA, and cardiolipin were all negative. Serum complement levels were normal.